Pull fbdev updates from Helge Deller:
"Beside the removal of the Hercules monochrome ISA graphics driver and
the corresponding text console driver, there is just the typical
maintanance with smaller driver fixes and cleanups:
Removal of drivers:
- Hercules monochrome ISA graphics adapter driver (Ethan Nelson-Moore)
- Hercules mdacon console driver (Ethan Nelson-Moore)
Changes affecting many drivers at once:
- possible memory leak fixes in various drivers (Abdun Nihaal)
- many conversions to use strscpy() (David Laight)
- Use named initializers in drivers (Uwe Kleine-König)
Code fixes:
- fbcon: don't suspend/resume when vc is graphics mode (Lu Yao)
- modedb: fix a possible UAF in fb_find_mode() (Tuo Li)
- modedb: Fix entry for 1920x1080-60 mode (Steffen Persvold)
- arm: Export acorndata_8x8 font symbol for bootloader (Helge Deller)
- omap2: fix use-after-free in omapfb_mmap (Hongling Zeng)
Cleanups:
- pxa168fb: use devm_ioremap_resource() (Alberto Arostegui)
- provice helpers for fb_set_var() and fb_blank() and fbcon updates
(Thomas Zimmermann)
- fbcon: Use correct type for vc_resize() return value (Jiacheng Yu)
- chipsfb: add missing MODULE_DESCRIPTION() macro (Rahman Mahmutović)
- sunxvr2500: replace printk with device-aware logging functions
(Rahman Mahmutović)
- sm712: Fix operator precedence in big_swap macro (Li RongQing)
- imxfb: Use of_device_get_match_data() (Rosen Penev)
- atmel_lcdfb: Use of_device_get_match_data() (Rosen Penev)
Documentation fixes:
- grvga: Fix CLUT register address offset in comment (Eduardo Silva)
- omap/dss: Fix stale modedb.c path (Costa Shulyupin)
- correct CONFIG_FB_TILEBLITTING macro name in #endif comment (Ethan
Nelson-Moore)"
* tag 'fbdev-for-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev: (43 commits)
fbdev: modedb: Fix misaligned fields in the 1920x1080-60 mode
fbdev: modedb: fix a possible UAF in fb_find_mode()
fbdev: s3fb: Use strscpy() to copy strings into arrays
fbdev: sm501fb: Fix buffer errors in OF binding code
fbcon: correct CONFIG_FB_TILEBLITTING macro name in #endif comment
fbdev/arm: Export acorndata_8x8 font symbol for bootloader
fbdev: mmpfb: Use strscpy() to copy device name
fbdev: sisfb: Replace strlen() strcpy() pair with strscpy()
fbdev: rivafb: Use strscpy() to copy device name
fbdev: cyber2000fb: Use strscpy() to copy device name
fbdev: atmel_lcdfb: Use strscpy() to copy device name
fbdev: Do not export fbcon from fbdev
fbdev: Wrap fbcon updates from vga-switcheroo in helper
fbdev: Wrap user-invoked calls to fb_blank() in helper
fbdev: Wrap user-invoked calls to fb_set_var() in helper
fbdev: omap2: fix use-after-free in omapfb_mmap
docs: omap/dss: Fix stale modedb.c path
fbdev: pxa168fb: use devm_ioremap_resource() for MMIO
fbdev: grvga: Fix CLUT register address offset in comment
fbdev: sunxvr2500: replace printk with device-aware logging functions
...
Pull s390 updates from Alexander Gordeev:
- Use CIO device online variable instead of the internal FSM state to
determine device availability during purge operations
- Remove extra check of task_stack_page() because try_get_task_stack()
already takes care of that when reading /proc/<pid>/wchan
- Allow user-space to use the new SCLP action qualifier 4 for to
provide NVMe SMART log data to the platform.
- Send AP CHANGE uevents on successful bind and successful association
to notify user-space about SE operations on AP queue devices
- Add an s390dbf kernel parameter to configure debug log levels and
area sizes during early boot
- On arm64 the empty zero page is going to be mapped read-only. Do the
same for s390 with an explicit set_memory_ro() call
- Improve s390-specific bcr_serialize() and cpu_relax() implementations
- Remove all unused variables to avoid allmodconfig W=1 build fails
with latest clang-23
- Cleanup default Kconfig values for s390 selftests
- Add a s390-tod trace clock to allow comparing trace timestamps
between different systems or virtual machines on s390
- Remove the s390 implementation of strlcat() in favor of the generic
variant
- Make consistent the calling order between
page_table_check_pte_clear() and secure page conversion across all
code paths
- Rearrange some fields within AP and zcrypt structs to reduce memory
consumption and unused holes
- Shorten GR_NUM and VX_NUM macros and move them to a separate header
- Replace __get_free_page() with kmalloc() in few sources
- Introduce an infrastructure for more efficient this_cpu operations.
Eliminate conditional branches when PREEMPT_NONE is removed
- Enable Rust support
- Use z10 as minimum architecture level, similar to the boot code, to
enforce a defined architecture level set
- Improve and convert various mem*() helper functions to C. For that
add .noinstr.text section to avoid orphaned warnings from the linker
- Fix the function pointer type in __ret_from_fork() to correct the
indirect call to match kernel thread return type of int
- Revert support for DCACHE_WORD_ACCESS to avoid an endless exception
loop on read from donated Ultravisor pages at unaligned addresses
* tag 's390-7.2-1' of gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux: (52 commits)
s390: Revert support for DCACHE_WORD_ACCESS
s390/process: Fix kernel thread function pointer type
s390/tishift: Convert __ashlti3(), __ashrti3(), __lshrti3() to C
s390/memmove: Optimize backward copy case
s390/string: Convert memset(16|32|64)() to C
s390/string: Convert memcpy() to C
s390/string: Convert memset() to C
s390/string: Convert memmove() to C
s390/string: Add -ffreestanding compile option to string.o
s390: Add .noinstr.text to boot and purgatory linker scripts
s390/purgatory: Enforce z10 minimum architecture level
s390: Enable Rust support
s390/cmpxchg: Fix KASAN stack-out-of-bounds in atomic helpers
rust: helpers: Add memchr wrapper for string operations
rust/bindgen_parameters: Mark s390 types as opaque to prevent repr conflicts
s390/jump_label: Implement ARCH_STATIC_BRANCH_JUMP_ASM and ARCH_STATIC_BRANCH_ASM macros
s390/bug: Provide ARCH_WARN_ASM for Rust WARN/BUG support
s390/ap: Fix locking issue in SE bind and associate sysfs functions
s390/percpu: Provide arch_this_cpu_write() implementation
s390/percpu: Provide arch_this_cpu_read() implementation
...
Pull driver core updates from Danilo Krummrich:
"Deferred probe:
- Fix race where deferred probe timeout work could be permanently
canceled by using mod_delayed_work()
- Fix missing jiffies conversion in deferred_probe_extend_timeout()
- Guard timeout extension with delayed_work_pending() to prevent
premature firing
- Use system_percpu_wq instead of the deprecated system_wq
- Update deferred_probe_timeout documentation
device:
- Replace direct struct device bitfield access (can_match, dma_iommu,
dma_skip_sync, dma_ops_bypass, state_synced, dma_coherent,
of_node_reused, offline, offline_disabled) with flag-based
accessors using bit operations
- Reject devices with unregistered buses
- Delete unused DEVICE_ATTR_PREALLOC()
- Add low-level device attribute macros with const show/store
callbacks, allowing device attributes to reside in read-only memory
- Move core device attributes to read-only memory
- Constify group array pointers in driver_add_groups() /
driver_remove_groups(), struct bus_type, and struct device_driver
device property:
- Fix fwnode reference leak in fwnode_graph_get_endpoint_by_id()
- Initialize all fields of fwnode_handle in fwnode_init()
- Provide swnode_get()/swnode_put() wrappers around kobject_get/put()
- Allow passing struct software_node_ref_args pointers directly to
PROPERTY_ENTRY_REF()
driver_override:
- Migrate amba, cdx, vmbus, and rpmsg to the generic driver_override
infrastructure, fixing a UAF from unsynchronized access to
driver_override in bus match() callbacks
- Remove the now-unused driver_set_override()
firmware loader:
- Fix recursive lock deadlock in device_cache_fw_images() when async
work falls back to synchronous execution
- Fix device reference leak in firmware_upload_register()
platform:
- Pass KBUILD_MODNAME through the platform driver registration macro
to create module symlinks in sysfs for built-in drivers; move
module_kset initialization to a pure_initcall and tegra cbb
registration to core_initcall to ensure correct ordering
- Pass THIS_MODULE implicitly through a coresight_init_driver() macro
sysfs:
- Upgrade OOB write detection in sysfs_kf_seq_show() from printk to
WARN
- Add return value clamping to sysfs_kf_read()
Rust:
- ACPI:
Fix missing match data for PRP0001 by exporting
acpi_of_match_device()
- Auxiliary:
Replace drvdata() with dedicated registration data on
auxiliary_device. drvdata() exposed the driver's bus device private
data beyond the driver's own scope, creating ordering constraints
and forcing the data to outlive all registrations that access it.
Registration data is instead scoped structurally to the
Registration object, making lifecycle ordering enforced by
construction rather than convention.
- Rust-native device driver lifetimes (HRT):
Allow Rust device drivers to carry a lifetime parameter on their
bus device private data, tied to the device binding scope -- the
interval during which a bus device is bound to a driver. Device
resources like pci::Bar<'a> and IoMem<'a> can be stored directly in
the driver's bus device private data with a lifetime bounded by the
binding scope, so the compiler enforces at build time that they do
not outlive the binding. This removes Devres indirection from every
access site and eliminates try_access() failure paths in
destructors.
Bus driver traits use a Generic Associated Type (GAT) Data<'bound>
to introduce the lifetime on the private data, rather than
parameterizing the Driver trait itself. Auxiliary registration
data, where the lifetime is not introduced by a trait callback but
must be threaded through Registration, uses the ForLt trait (a
type-level abstraction for types generic over a lifetime).
Misc:
- Fix DT overlayed devices not probing by reverting the broken
treewide overlay fix and re-running fw_devlink consumer pickup when
an overlay is applied to a bound device
- Use root_device_register() for faux bus root device; add sanity
check for failed bus init
- Fix dev_has_sync_state() data race with READ_ONCE() and move it to
base.h
- Avoid spurious device_links warning when removing a device while
its supplier is unbinding
- Switch ISA bus to dynamic root device
- Fix suspicious RCU usage in kernfs_put()
- Remove devcoredump exit callback
- Constify devfreq_event_class"
* tag 'driver-core-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core: (81 commits)
software node: allow passing reference args to PROPERTY_ENTRY_REF()
driver core: platform: set mod_name in driver registration
coresight: pass THIS_MODULE implicitly through a macro
kernel: param: initialize module_kset in a pure_initcall
soc/tegra: cbb: Move driver registration from pure_initcall to core_initcall
firmware_loader: Fix recursive lock in device_cache_fw_images()
driver core: Use system_percpu_wq instead of system_wq
driver core: remove driver_set_override()
rpmsg: use generic driver_override infrastructure
Drivers: hv: vmbus: use generic driver_override infrastructure
cdx: use generic driver_override infrastructure
amba: use generic driver_override infrastructure
rust: devres: add 'static bound to Devres<T>
samples: rust: rust_driver_auxiliary: showcase lifetime-bound registration data
rust: auxiliary: generalize Registration over ForLt
rust: types: add `ForLt` trait for higher-ranked lifetime support
gpu: nova-core: separate driver type from driver data
samples: rust: rust_driver_pci: use HRT lifetime for Bar
rust: io: make IoMem and ExclusiveIoMem lifetime-parameterized
rust: pci: make Bar lifetime-parameterized
...
hvc_iucv_alloc() allocates a send staging buffer for accumulating
outbound terminal characters before they are copied into a separate
IUCV message buffer for transmission to the hypervisor. The staging
buffer itself is never passed to any IUCV function.
This buffer can be allocated with kmalloc() as there's nothing special
about it to go directly to the page allocator.
kmalloc() provides a better API that does not require ugly casts and
kfree() does not need to know the size of the freed object.
Performance difference between kmalloc() and __get_free_pages() is not
measurable as both allocators take an object/page from a per-CPU list for
fast path allocations.
For the slow path the performance is anyway determined by the amount of
reclaim involved rather than by what allocator is used.
Replace use of get_zeroed_page() with kzalloc() and free_page() with
kfree().
Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Prevent a crash from happening as the first serial port is initialised:
Console: switching to mono frame buffer device 160x64
fb0: PMAG-AA frame buffer device at tc0
DECstation Z85C30 serial driver version 0.10
CPU 0 Unable to handle kernel paging request at virtual address 0000002c, epc == 803ab00c, ra == 803aafe0
Oops[#1]:
CPU: 0 PID: 1 Comm: swapper Not tainted 6.4.0-rc3-00031-g84a9582fd203-dirty #57
$ 0 : 00000000 10012c00 803aaeb0 00000000
$ 4 : 80e12f60 80e12f50 80e12f58 81000030
$ 8 : 00000000 805ff37c 00000000 33433538
$12 : 65732030 00000006 80c2915d 6c616972
$16 : 80e12f00 807b7630 00000000 00000000
$20 : 00000004 00000348 000001a0 807623b8
$24 : 00000018 00000000
$28 : 80c24000 80c25d60 8078b148 803aafe0
Hi : 00000000
Lo : 00000000
epc : 803ab00c serial_base_ctrl_add+0x78/0xf4
ra : 803aafe0 serial_base_ctrl_add+0x4c/0xf4
Status: 10012c03 KERNEL EXL IE
Cause : 00000008 (ExcCode 02)
BadVA : 0000002c
PrId : 00000440 (R4400SC)
Modules linked in:
Process swapper (pid: 1, threadinfo=(ptrval), task=(ptrval), tls=00000000)
Stack : 80760000 00000cc0 00400044 00400040 803aa02c 80d61ab8 00000000 807b7630
80760000 807623b8 807b7628 803aa644 80386998 00000000 80e17780 80220f68
80e17780 80d61ab8 80c17d80 80e17780 80e17780 8063c798 80e17780 80383fa0
00000010 80e17780 00000000 80386998 807a0000 00000000 00400040 8038f848
807623b8 80d61ab8 00000004 80e17780 00000000 803a68e4 80c25e2c 803bb884
...
Call Trace:
[<803ab00c>] serial_base_ctrl_add+0x78/0xf4
[<803aa644>] serial_core_register_port+0x174/0x69c
[<8077e9ac>] zs_init+0xc8/0xfc
[<800404d4>] do_one_initcall+0x40/0x2ac
[<8076cecc>] kernel_init_freeable+0x1e4/0x270
[<80605bec>] kernel_init+0x20/0x108
[<800431e8>] ret_from_kernel_thread+0x14/0x1c
Code: 2442aeb0 ae120024 ae0200d0 <8c67002c> 50e00001 8c670000 3c06806e 3c05806e afb30010
---[ end trace 0000000000000000 ]---
(report at the offending commit) -- where a pointer is dereferenced that
has been derived from a null pointer to the port's parent device.
Since no device is available with legacy probing and it's not anymore a
preferable way to discover devices anyway, switch the driver to using a
platform device and use it as the port's parent device. Update resource
handling accordingly and only request the actual span of addresses used
within the slot, which will have had its resource already requested by
generic platform device code.
Use platform_driver_probe() not just because SCC devices are fixed with
solder on board and not straightforward to remove, but foremost because
the associated TTY's major device number is the same as used by the dz
driver and the first driver to claim it will prevent the other one from
using it. Either one DZ device or some SCC devices will be present in a
given system but never both at a time, and therefore we want the major
device number to be claimed by the first driver to actually successfully
bind to its device and platform_driver_probe() is a way to fulfil that.
An unfortunate consequence of the switch to a platform device is we now
hand the console over from the bootconsole much later in the bootstrap.
The firmware console handler appears good enough though to work so late
and in particular with interrupts enabled.
Since there is one way only remaining to reach zs_reset() now, remove
the port initialisation marker as no longer needed and go through the
channel reset unconditionally.
Fixes: 84a9582fd2 ("serial: core: Start managing serial controllers to enable runtime PM")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # needs to use .remove_new for <= 6.10
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062328480.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Prevent a crash from happening as the first serial port is initialised:
Console: switching to colour frame buffer device 160x64
tgafb: SFB+ detected, rev=0x02
fb0: Digital ZLX-E1 frame buffer device at 0x1e000000
DECstation DZ serial driver version 1.04
CPU 0 Unable to handle kernel paging request at virtual address 000000bc, epc == 8048b3a4, ra == 80470a78
Oops[#1]:
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.19.0-dirty #35 NONE
$ 0 : 00000000 1000ac00 00000004 804707ac
$ 4 : 00000000 80e20850 80e20858 81000030
$ 8 : 00000000 8072c81c 00000008 fefefeff
$12 : 6c616972 00000006 80c5917f 69726420
$16 : 80e20800 00000000 808f8968 80e20800
$20 : 00000000 807f5a90 808b0094 808d3bc8
$24 : 00000018 80479030
$28 : 80c2e000 80c2fd70 00000069 80470a78
Hi : 00000004
Lo : 00000000
epc : 8048b3a4 __dev_fwnode+0x0/0xc
ra : 80470a78 serial_base_ctrl_add+0xa0/0x168
Status: 1000ac04 IEp
Cause : 30000008 (ExcCode 02)
BadVA : 000000bc
PrId : 00000220 (R3000)
Modules linked in:
Process swapper/0 (pid: 1, threadinfo=(ptrval), task=(ptrval), tls=00000000)
Stack : 00400044 00400040 8046f4cc 00000000 808a6148 808a0000 808f8968 8086983c
808e0000 8046fc84 1000ac01 00000028 80e20700 802ba3f8 80e20700 80d34a94
80c1b900 80e20700 80e20700 80e20700 80e20700 80444650 00000000 00000000
00000000 807f5a90 808b0094 80447080 00400040 808e0000 80d34a94 808a6148
80d34a94 00000004 80e20700 00000000 8076974c 80469810 80c2fe3c 1000ac01
...
Call Trace:
[<8048b3a4>] __dev_fwnode+0x0/0xc
[<80470a78>] serial_base_ctrl_add+0xa0/0x168
[<8046fc84>] serial_core_register_port+0x1c8/0x974
[<808c6af0>] dz_init+0x74/0xc8
[<800470e0>] do_one_initcall+0x44/0x2d4
[<808b111c>] kernel_init_freeable+0x258/0x308
[<8072e434>] kernel_init+0x20/0x114
[<80049cd0>] ret_from_kernel_thread+0x14/0x1c
Code: 27bd0018 03e00008 2402ffea <8c8200bc> 03e00008 00000000 27bdffc0 afbe0038 afb30024
---[ end trace 0000000000000000 ]---
-- where a pointer is dereferenced that has been derived from a null
pointer to the port's parent device.
Since no device is available with legacy probing and it's not anymore a
preferable way to discover devices anyway, switch the driver to using a
platform device and use it as the port's parent device. Update resource
handling accordingly and only request the actual span of addresses used
within the slot, which will have had its resource already requested by
generic platform device code.
Use platform_driver_probe() not just because the DZ device is fixed with
solder on board and not straightforward to remove, but foremost because
the associated TTY's major device number is the same as used by the zs
driver and the first driver to claim it will prevent the other one from
using it. Either one DZ device or some SCC devices will be present in a
given system but never both at a time, and therefore we want the major
device number to be claimed by the first driver to actually successfully
bind to its device and platform_driver_probe() is a way to fulfil that.
An unfortunate consequence of the switch to a platform device is we now
hand the console over from the bootconsole much later in the bootstrap.
The firmware console handler appears good enough though to work so late
and in particular with interrupts enabled.
Conversely only starting the console port so late lets the reset code
fully utilise our delay handlers, so switch from udelay() to fsleep()
for transmitter draining so as to avoid busy-waiting for an excessive
amount of time.
Fixes: 84a9582fd2 ("serial: core: Start managing serial controllers to enable runtime PM")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # needs to use .remove_new for <= 6.10
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062326540.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Switch the driver to using the channel reset rather than hardware reset,
simplifying handling by removing an interference between channels that
causes the other channel to become uninitialised afterwards.
There is little difference between the two kinds of reset in terms of
register settings that result, and we initialise the whole register set
right away anyway. However this prevents a hang from happening should
the console output handler in the firmware try to access the other port
whose transmitter has been disabled and line parameters messed up.
For example this will happen if the keyboard port (port A) is chosen for
the system console, unusually but not insanely for a headless system, as
the port is wired to a standard DA-15 connector and an adapter can be
easily made. Or with the next change in place this would happen for the
regular console port (port B), since the keyboard port (port A) will be
initialised first.
Just remove the unnecessary complication then, a channel reset is good
enough. We still need the initialisation marker, now per channel rather
than per SCC, as for the console port zs_reset() will be called twice:
once early on via zs_serial_console_init() for the console setup only,
and then again via zs_config_port() as the port is associated with a TTY
device.
Fixes: 8b4a40809e ("zs: move to the serial subsystem")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.23+
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062323430.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Calling zs_reset() in the course of setting up the serial device causes
line parameters to be reset and the transmitter disabled. We've been
lucky in that no message is usually produced to the kernel log between
this call and the later call to uart_set_options() in the course of
console setup done by zs_serial_console_init(), or the system would hang
as the console output handler in the firmware tried to access a port the
transmitter of which has been disabled and line parameters messed up.
This will change with the next change to the driver, so fix zs_reset()
such that line parameters are set for 9600n8 console operation as with
the system firmware and the transmitter re-enabled after reset. This
also means zs_pm() serves no purpose anymore, so drop it.
Fixes: 8b4a40809e ("zs: move to the serial subsystem")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.23+
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062308040.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Calling dz_reset() in the course of setting up the serial device causes
line parameters to be reset and the transmitter disabled. We've been
lucky in that no message is usually produced to the kernel log between
this call and the later call to uart_set_options() in the course of
console setup done by dz_serial_console_init(), or the system would hang
as the console output handler in the firmware tried to access a port the
transmitter of which has been disabled and line parameters messed up.
This will change with the next change to the driver, so fix dz_reset()
such that line parameters are set for 9600n8 console operation as with
the system firmware and the transmitter re-enabled after reset. This
also means dz_pm() serves no purpose anymore, so drop it.
Fixes: e6ee512f5a ("dz.c: Resource management")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.25+
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062302010.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the DZ interface as implemented by the DC7085 gate array the serial
transmitters are double buffered, meaning that at the time a transmitter
is ready to accept the next character there is one in the transmit shift
register still being sent to the line. Issuing a master clear at this
time causes this character to be lost, so wait an extra amount of time
sufficient for the transmit shift register to drain at 9600bps, which is
the baud rate setting used by the firmware console.
Mind the specified 1.4us TRDY recovery time in the course and continue
using iob() as the completion barrier, since the platforms involved use
a write buffer that can delay and combine writes, and reorder them with
respect to reads regardless of the MMIO locations accessed and we still
lack a platform-independent handler for that.
When called from dz_serial_console_init() this is too early for fsleep()
to work and even before lpj has been calculated and therefore the delay
is actually not sufficient for the transmitter to drain and is merely a
placeholder now. This will be addressed in a follow-up change.
Fixes: e6ee512f5a ("dz.c: Resource management")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.25+
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062259080.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dw8250_handle_irq() calls serial8250_handle_irq_locked() with the port
lock held via guard(uart_port_lock_irqsave). The guard destructor is
plain uart_port_unlock_irqrestore(), so a SysRq character captured into
port->sysrq_ch by uart_prepare_sysrq_char() is dropped without ever
being dispatched to handle_sysrq().
This is the same regression pattern as in serial8250_handle_irq(),
introduced when 883c5a2bc9 ("serial: 8250_dw: Rework
dw8250_handle_irq() locking and IIR handling") moved the function to
the guard()-based locking scheme without using the sysrq-aware unlock
helper.
Switch to guard(uart_port_lock_check_sysrq_irqsave) so that captured
sysrq_ch is dispatched on scope exit, matching the fix in
serial8250_handle_irq().
Fixes: 883c5a2bc9 ("serial: 8250_dw: Rework dw8250_handle_irq() locking and IIR handling")
Cc: stable@vger.kernel.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jacques Nilo <jnilo@free.fr>
Link: https://patch.msgid.link/ed56fcaf4af24e4ed011a7bce206e0182acb761c.1778675349.git.jnilo@free.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial8250_handle_irq() captures a SysRq character into port->sysrq_ch
inside serial8250_handle_irq_locked() via uart_prepare_sysrq_char()
(reached from serial8250_read_char()). Dispatch of that captured
character to handle_sysrq() is expected to happen at port-unlock time,
through uart_unlock_and_check_sysrq[_irqrestore]().
After commit 8324a54f60 ("serial: 8250: Add
serial8250_handle_irq_locked()") the function was reduced to a wrapper
that takes the port lock via guard(uart_port_lock_irqsave) whose
destructor is plain uart_port_unlock_irqrestore(). The sysrq-aware
unlock helper is no longer called, so port->sysrq_ch is captured but
never dispatched: BREAK + SysRq key is consumed silently.
This was the very condition Johan Hovold's 853a9ae29e ("serial:
8250: fix handle_irq locking", 2021) introduced
uart_unlock_and_check_sysrq_irqrestore() to address.
Switch to the new guard(uart_port_lock_check_sysrq_irqsave), whose
destructor is the sysrq-aware unlock helper, restoring the pre-split
behaviour. Update the Context: comment on serial8250_handle_irq_locked()
so future HW-specific 8250 wrappers know to use the same guard or the
explicit sysrq-aware unlock.
Verified on RTL8196E with CONFIG_MAGIC_SYSRQ_SERIAL=y: BREAK + 'h' on
the console UART produces the SysRq help dump in dmesg and the brk
counter in /proc/tty/driver/serial increments correctly.
Fixes: 8324a54f60 ("serial: 8250: Add serial8250_handle_irq_locked()")
Cc: stable@vger.kernel.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jacques Nilo <jnilo@free.fr>
Link: https://patch.msgid.link/52692ae6c3501f7940347cef364ad7fcacaab7e5.1778675349.git.jnilo@free.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sashiko identified a deadlock when the console flow is engaged [1].
When console flow control is enabled (UPF_CONS_FLOW),
s3c24xx_serial_stop_tx() calls s3c24xx_serial_rx_enable() and
s3c24xx_serial_start_tx() calls s3c24xx_serial_rx_disable().
The serial core framework invokes the .stop_tx() and .start_tx()
callbacks with the port->lock spinlock already held. Furthermore, all
internal driver paths that invoke stop_tx (such as the DMA TX
completion handler s3c24xx_serial_tx_dma_complete() or the PIO TX IRQ
handler s3c24xx_serial_tx_irq()) also acquire port->lock prior to
calling it. (Note that s3c24xx_serial_start_tx() is only invoked by the
serial core).
However, s3c24xx_serial_rx_enable() and s3c24xx_serial_rx_disable()
unconditionally attempt to acquire port->lock again using
uart_port_lock_irqsave(). Since spinlocks are not recursive, this
causes a deadlock on the same CPU when console flow control is engaged.
Remove the redundant lock acquisition from both rx helper functions.
Cc: stable <stable@kernel.org>
Fixes: b497549a03 ("[ARM] S3C24XX: Split serial driver into core and per-cpu drivers")
Reported-by: John Ogness <john.ogness@linutronix.de>
Closes: https://sashiko.dev/#/patchset/20260506121606.5805-1-john.ogness%40linutronix.de [1]
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://patch.msgid.link/20260515-samsung-tty-flow-control-deadlock-v1-1-93255edbc9bc@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
altera_jtaguart_probe() maps the register window before registering the
UART port, but it ignores failures from uart_add_one_port(). If port
registration fails, probe still returns success and the mapping remains
live until a later remove path that is not part of probe failure cleanup.
Return the uart_add_one_port() error and unmap the register window on
that failure path.
This issue was identified during our ongoing static-analysis research while
reviewing kernel code.
Fixes: 5bcd601049 ("serial: Add driver for the Altera JTAG UART")
Cc: stable <stable@kernel.org>
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
Link: https://patch.msgid.link/20260512065837.79528-1-mhun512@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The mdacon driver supports using ISA MDA or Hercules-compatible display
adapters as a secondary text console. This was commonly used in the
1990s and earlier for debugging software which took over the primary
display. It is highly unlikely anyone is doing so nowadays because
serial consoles and much better methods of debugging exist.
The driver is not enabled by any defconfig, nor any of the
dozens of distro configs collected at [1]. It has been relegated to VTs
13-16 since commit 0b9cf3aa6b ("mdacon messing up default vc's - set
default to vc13-16 again") in Linux 2.6.27 (and before Linux 2.5.53 -
see the link in the message of the above commit). The change in 2.6.27
was done because it was incorrectly detecting non-MDA adapters as MDA
and taking over all VTs, rendering them unusable.
Furthermore, vgacon supports using MDA/Hercules-compatible adapters as
the primary text console, so any systems with only one of these
adapters were already using vgacon and will not experience any loss in
functionality from the removal of this driver.
Given all of these factors, the mdacon driver is likely entirely
unused. Remove it.
[1] f0bee86a13
Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
When uart_flush_buffer() runs before the DMA completion IRQ is delivered,
the following race can occur (all steps serialized by uart_port_lock):
1. DMA starts: tx_remaining = N, kfifo contains N bytes
2. DMA completes in hardware; IRQ is pending but not yet delivered
3. uart_flush_buffer() acquires the port lock and calls kfifo_reset(),
making kfifo_len() = 0 while tx_remaining remains N
4. uart_flush_buffer() releases the port lock
5. DMA IRQ fires; handle_tx_dma() acquires the port lock and calls
uart_xmit_advance(uport, tx_remaining) on an empty kfifo
uart_xmit_advance() increments kfifo->out by tx_remaining. Since
kfifo_reset() already set both in and out to 0, out wraps past in,
causing kfifo_len() to return UART_XMIT_SIZE - tx_remaining. The next
start_tx_dma() call then submits a DMA transfer of stale buffer data.
Fix this by snapshotting kfifo_len() at the start of handle_tx_dma()
and skipping uart_xmit_advance() when fifo_len < tx_remaining, which
indicates the kfifo was reset by a preceding flush.
Fixes: 2aaa43c707 ("tty: serial: qcom-geni-serial: add support for serial engine DMA")
Cc: stable <stable@kernel.org>
Signed-off-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260506-serial-dma-stale-tx-buf-v1-1-e3ccb360d719@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
lpuart_start_rx_dma() allocates sport->rx_ring.buf with kzalloc() and
then maps a scatterlist via dma_map_sg(). On three subsequent error
paths the function returns directly without releasing those resources:
- when dma_map_sg() returns 0 (-EINVAL):
ring->buf is leaked.
- when dmaengine_slave_config() fails:
ring->buf and the DMA mapping are leaked.
- when dmaengine_prep_dma_cyclic() returns NULL:
ring->buf and the DMA mapping are leaked.
The sole cleanup path, lpuart_dma_rx_free(), is only reached when
lpuart_dma_rx_use is set, and the caller lpuart_rx_dma_startup() clears
that flag on failure of lpuart_start_rx_dma(). So these resources are
permanently leaked on every failure in this function. Repeated port
open/close or termios changes under error conditions will slowly consume
memory and leave stale streaming DMA mappings behind.
Fix it by introducing two error labels that unmap the scatterlist and
free the ring buffer as appropriate. While here, replace the misleading
-EFAULT (bad userspace pointer) returned when dmaengine_prep_dma_cyclic()
fails with the more accurate -ENOMEM, matching how other dmaengine users
in the tree treat this failure.
No functional change on the success path.
Fixes: 5887ad43ee ("tty: serial: fsl_lpuart: Use cyclic DMA for Rx")
Cc: stable <stable@kernel.org>
Signed-off-by: Shitalkumar Gandhi <shitalkumar.gandhi@cambiumnetworks.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260420135903.2062024-1-shitalkumar.gandhi@cambiumnetworks.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull tty/serial updates from Greg KH:
"Here is the set of tty and serial driver changes for 7.1-rc1.
Not much here this cycle, biggest thing is the removal of an old
driver that never got any actual hardware support (esp32), and the
second try to moving the tty ports to their own workqueues (first try
was in 7.0-rc1 but was reverted due to problems)
Otherwise it's just a small set of driver updates and some vt modifier
key enhancements.
All have been in linux-next for a while with no reported issues"
* tag 'tty-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (35 commits)
tty: serial: ip22zilog: Fix section mispatch warning
hvc/xen: Check console connection flag
serial: sh-sci: Add support for RZ/G3L RSCI
dt-bindings: serial: renesas,rsci: Document RZ/G3L SoC
tty: atmel_serial: update outdated reference to atmel_tasklet_func()
serial: xilinx_uartps: Drop unused include
serial: qcom-geni: drop stray newline format specifier
serial: 8250: loongson: Enable building on MIPS Loongson64
dt-bindings: serial: 8250: Add Loongson 3A4000 uart compatible
serial: 8250_fintek: Add support for F81214E
tty: tty_port: add workqueue to flip TTY buffer
vt: support ITU-T T.416 color subparameters
serial: qcom-geni: Fix RTS behavior with flow control
tty: serial: imx: keep dma request disabled before dma transfer setup
tty: serial: 8250: Add SystemBase Multi I/O cards
serial: pic32_uart: allow driver to be compiled on all architectures with COMPILE_TEST
serial: tegra: remove Kconfig dependency on APB DMA controller
dt-bindings: serial: amlogic,meson-uart: Add compatible string for A9
dt-bindings: serial: atmel,at91-usart: add microchip,lan9691-usart
serial: auart: check clk_enable() return in console write
...
Pull xen updates from Juergen Gross:
- fix an error path in drivers/xen/manage.c
- fix the Xen console driver solving a boot hangup when the console
backend isn't yet running
- comment fix in the Xen swiotlb driver
- hardening for Xen on Arm adding a more thorough validation
- cleanup of the Xen grant table code hiding suspend/resume code for
the case if CONFIG_HIBERNATE_CALLBACKS isn't defined
* tag 'for-linus-7.1-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/grant-table: guard gnttab_suspend/resume with CONFIG_HIBERNATE_CALLBACKS
hvc/xen: Check console connection flag
xen/swiotlb: fix stale reference to swiotlb_unmap_page()
xen/manage: unwind partial shutdown watcher setup on error
ARM: xen: validate hypervisor compatible before parsing its version
Pull fbdev updates from Helge Deller:
"A major refactorization by Thomas Zimmermann from SUSE regarding
handling of console font data, addition of helpers for console font
rotation and split into individual components for glyphs, fonts and
the overall fbcon state.
And there is the round of usual code cleanups and fixes:
Cleanups:
- atyfb: Remove unused fb_list (Geert Uytterhoeven)
- goldfishfb, wmt_ge_rops: use devm_platform_ioremap_resource() (Amin GATTOUT)
- matroxfb: Mark variable with __maybe_unused (Andy Shevchenko)
- omapfb: Add missing error check for clk_get() (Chen Ni)
- tdfxfb: Make the VGA register initialisation a bit more obvious (Daniel Palmer)
- macfb: Replace deprecated strcpy with strscpy (Thorsten Blum)
Fixes:
- tdfxfb, udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO (Greg Kroah-Hartman)
- omap2: fix inconsistent lock returns in omapfb_mmap (Hongling Zeng)
- viafb: check ioremap return value in viafb_lcd_get_mobile_state (Wang Jun)"
* tag 'fbdev-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev: (40 commits)
fbdev: udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO
fbdev: tdfxfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO
fbdev: omap2: fix inconsistent lock returns in omapfb_mmap
MAINTAINERS: Add dedicated entry for fbcon
fbcon: Put font-rotation state into separate struct
fbcon: Fill cursor mask in helper function
lib/fonts: Implement font rotation
lib/fonts: Refactor glyph-rotation helpers
lib/fonts: Refactor glyph-pattern helpers
lib/fonts: Implement glyph rotation
lib/fonts: Clean up Makefile
lib/fonts: Provide helpers for calculating glyph pitch and size
vt: Implement helpers for struct vc_font in source file
fbcon: Avoid OOB font access if console rotation fails
fbdev: atyfb: Remove unused fb_list
fbdev: matroxfb: Mark variable with __maybe_unused to avoid W=1 build break
fbdev: update help text for CONFIG_FB_NVIDIA
fbdev: omapfb: Add missing error check for clk_get()
fbdev: viafb: check ioremap return value in viafb_lcd_get_mobile_state
lib/fonts: Remove internal symbols and macros from public header file
...
Pull power sequencing updates from Bartosz Golaszewski:
"For this release we have an extension of the pwrseq-pcie-m2 driver
with support for PCIe M.2 Key E connectors.
The rest of the commits fulfill a supporting role: document the
hardware in DT bindings, provide required serdev helpers (this has
been provided in an immutable branch to Rob Herring so you may see it
in his PR as well) and is followed up by some Kconfig fixes from Arnd.
Summary:
- add support for the PCIe M.2 Key E connectors in pwrseq-pcie-m2
- describe PCIe M.2 Mechanical Key E connectors in DT bindings
- add serdev helpers for looking up devices by OF nodes
- minor serdev core rework to enable support for PCIe M.2 Key E
connectors"
* tag 'pwrseq-updates-for-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
power: sequencing: pcie-m2: add SERIAL_DEV_BUS dependency
power: sequencing: pcie-m2: enforce PCI and OF dependencies
power: sequencing: pcie-m2: Create serdev device for WCN7850 bluetooth
power: sequencing: pcie-m2: Add support for PCIe M.2 Key E connectors
dt-bindings: connector: Add PCIe M.2 Mechanical Key E connector
dt-bindings: serial: Document the graph port
serdev: Do not return -ENODEV from of_serdev_register_devices() if external connector is used
serdev: Add an API to find the serdev controller associated with the devicetree node
serdev: Convert to_serdev_*() helpers to macros and use container_of_const()
When the console out buffer is filled, __write_console() will return 0
as it cannot send any data. domU_write_console() will then spin in
`while (len)` as len doesn't decrement until xenconsoled attaches. This
would block a domU and nullify the parallelism of Hyperlaunch until dom0
userspace starts xenconsoled, which empties the buffer.
Xen 4.21 added a connection field to the xen console page. This is set
to XENCONSOLE_DISCONNECTED (1) when a domain is built, and xenconsoled
will set it to XENCONSOLE_CONNECTED (0) when it connects.
Update the hvc_xen driver to check the field. When the field is
disconnected, drop the write with -ENOTCONN. We only drop the write
when the field is XENCONSOLE_DISCONNECTED (1) to try for maximum
compatibility. The Xen toolstack has historically zero initialized the
console, so it should see XENCONSOLE_CONNECTED (0) by default. If an
implemenation used uninitialized memory, only checking for
XENCONSOLE_DISCONNECTED could have the lowest chance of not connecting.
This lets the hyperlaunched domU boot without stalling. Once dom0
starts xenconsoled, xl console can be used to access the domU's hvc0.
Paritally sync console.h from xen.git to bring in the new field.
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Message-ID: <20260318235326.14568-1-jason.andryuk@amd.com>
Implement pitch and size calculation for a single font glyph in the
new helpers font_glyph_pitch() and font_glyph_size(). Replace the
instances where the calculations are open-coded.
Note that in the case of fbcon console rotation, the parameters for
a glyph's width and height might be reversed. This is intentional.
v2:
- fix typos in commit message
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Move the helpers vc_font_pitch() and vc_font_size() from the VT
header file into source file. They are not called very often, so
there's no benefit in keeping them in the headers. Also avoids
including <linux/math.h> from the header.
v2:
- fix typo in commit description
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Instead of discarding the saved unicode buffer when the console was
resized while in the alternate screen, resize it to the current
dimensions using vc_uniscr_copy_area() to preserve its content. This
properly restores the unicode screen on alt screen exit rather than
lazily rebuilding it from a lossy reverse glyph translation.
On allocation failure the stale buffer is freed and vc_uni_lines is
set to NULL so it gets lazily rebuilt via vc_uniscr_check() when next
needed.
Fixes: 40014493ce ("vt: discard stale unicode buffer on alt screen exit after resize")
Cc: stable <stable@kernel.org>
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Link: https://patch.msgid.link/3nsr334n-079q-125n-7807-n4nq818758ns@syhkavp.arg
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When enter_alt_screen() saves vc_uni_lines into vc_saved_uni_lines and
sets vc_uni_lines to NULL, a subsequent console resize via vc_do_resize()
skips reallocating the unicode buffer because vc_uni_lines is NULL.
However, vc_saved_uni_lines still points to the old buffer allocated for
the original dimensions.
When leave_alt_screen() later restores vc_saved_uni_lines, the buffer
dimensions no longer match vc_rows/vc_cols. Any operation that iterates
over the unicode buffer using the current dimensions (e.g. csi_J clearing
the screen) will access memory out of bounds, causing a kernel oops:
BUG: unable to handle page fault for address: 0x0000002000000020
RIP: 0010:csi_J+0x133/0x2d0
The faulting address 0x0000002000000020 is two adjacent u32 space
characters (0x20) interpreted as a pointer, read from the row data area
past the end of the 25-entry pointer array in a buffer allocated for
80x25 but accessed with 240x67 dimensions.
Fix this by checking whether the console dimensions changed while in the
alternate screen. If they did, free the stale saved buffer instead of
restoring it. The unicode screen will be lazily rebuilt via
vc_uniscr_check() when next needed.
Fixes: 5eb608319b ("vt: save/restore unicode screen buffer for alternate screen")
Cc: stable <stable@kernel.org>
Tested-by: Liav Mordouch <liavmordouch@gmail.com>
Signed-off-by: Liav Mordouch <liavmordouch@gmail.com>
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Link: https://patch.msgid.link/20260327170204.29706-1-liavmordouch@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the console out buffer is filled, __write_console() will return 0
as it cannot send any data. domU_write_console() will then spin in
`while (len)` as len doesn't decrement until xenconsoled attaches. This
would block a domU and nullify the parallelism of Hyperlaunch until dom0
userspace starts xenconsoled, which empties the buffer.
Xen 4.21 added a connection field to the xen console page. This is set
to XENCONSOLE_DISCONNECTED (1) when a domain is built, and xenconsoled
will set it to XENCONSOLE_CONNECTED (0) when it connects.
Update the hvc_xen driver to check the field. When the field is
disconnected, drop the write with -ENOTCONN. We only drop the write
when the field is XENCONSOLE_DISCONNECTED (1) to try for maximum
compatibility. The Xen toolstack has historically zero initialized the
console, so it should see XENCONSOLE_CONNECTED (0) by default. If an
implemenation used uninitialized memory, only checking for
XENCONSOLE_DISCONNECTED could have the lowest chance of not connecting.
This lets the hyperlaunched domU boot without stalling. Once dom0
starts xenconsoled, xl console can be used to access the domU's hvc0.
Paritally sync console.h from xen.git to bring in the new field.
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Link: https://patch.msgid.link/20260318235326.14568-1-jason.andryuk@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for RZ/G3L RSCI. The RSCI IP found on the RZ/G3L SoC is
similar to RZ/G3E, but it has 3 clocks (2 module clocks + 1 external
clock) instead of 6 clocks (5 module clocks + 1 external clock) on the
RZ/G3E. Both RZ/G3L and RZ/G3E have a 32-bit FIFO, but RZ/G3L has a
single TCLK with internal dividers, whereas the RZ/G3E has explicit
clocks for TCLK and its dividers. Add a new port type
RSCI_PORT_SCIF32_SINGLE_TCLK to handle this clock difference.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260312082708.98835-3-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The alternate screen support added by commit 23743ba647 ("vt: add
support for smput/rmput escape codes") only saves and restores the
regular screen buffer (vc_origin), but completely ignores the corresponding
unicode screen buffer (vc_uni_lines) creating a messed-up display.
Add vc_saved_uni_lines to save the unicode screen buffer when entering
the alternate screen, and restore it when leaving. Also ensure proper
cleanup in reset_terminal() and vc_deallocate().
Fixes: 23743ba647 ("vt: add support for smput/rmput escape codes")
Cc: stable <stable@kernel.org>
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://patch.msgid.link/5o2p6qp3-91pq-0p17-or02-1oors4417ns7@onlyvoer.pbz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
DW UART cannot write to LCR, DLL, and DLH while BUSY is asserted.
Existance of BUSY depends on uart_16550_compatible, if UART HW is
configured with it those registers can always be written.
There currently is dw8250_force_idle() which attempts to achieve
non-BUSY state by disabling FIFO, however, the solution is unreliable
when Rx keeps getting more and more characters.
Create a sequence of operations that ensures UART cannot keep BUSY
asserted indefinitely. The new sequence relies on enabling loopback mode
temporarily to prevent incoming Rx characters keeping UART BUSY.
Ensure no Tx in ongoing while the UART is switches into the loopback
mode (requires exporting serial8250_fifo_wait_for_lsr_thre() and adding
DMA Tx pause/resume functions).
According to tests performed by Adriana Nicolae <adriana@arista.com>,
simply disabling FIFO or clearing FIFOs only once does not always
ensure BUSY is deasserted but up to two tries may be needed. This could
be related to ongoing Rx of a character (a guess, not known for sure).
Therefore, retry FIFO clearing a few times (retry limit 4 is arbitrary
number but using, e.g., p->fifosize seems overly large). Tests
performed by others did not exhibit similar challenge but it does not
seem harmful to leave the FIFO clearing loop in place for all DW UARTs
with BUSY functionality.
Use the new dw8250_idle_enter/exit() to do divisor writes and LCR
writes. In case of plain LCR writes, opportunistically try to update
LCR first and only invoke dw8250_idle_enter() if the write did not
succeed (it has been observed that in practice most LCR writes do
succeed without complications).
This issue was first reported by qianfan Zhao who put lots of debugging
effort into understanding the solution space.
Fixes: c49436b657 ("serial: 8250_dw: Improve unwritable LCR workaround")
Fixes: 7d4008ebb1 ("tty: add a DesignWare 8250 driver")
Cc: stable <stable@kernel.org>
Reported-by: qianfan Zhao <qianfanguijin@163.com>
Link: https://lore.kernel.org/linux-serial/289bb78a-7509-1c5c-2923-a04ed3b6487d@163.com/
Reported-by: Adriana Nicolae <adriana@arista.com>
Link: https://lore.kernel.org/linux-serial/20250819182322.3451959-1-adriana@arista.com/
Reported-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-8-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When DW UART is !uart_16550_compatible, it can indicate BUSY at any
point (when under constant Rx pressure) unless a complex sequence of
steps is performed. Any LCR write can run a foul with the condition
that prevents writing LCR while the UART is BUSY, which triggers
BUSY_DETECT interrupt that seems unmaskable using IER bits.
Normal flow is that dw8250_handle_irq() handles BUSY_DETECT condition
by reading USR register. This BUSY feature, however, breaks the
assumptions made in serial8250_do_shutdown(), which runs
synchronize_irq() after clearing IER and assumes no interrupts can
occur after that point but then proceeds to update LCR, which on DW
UART can trigger an interrupt.
If serial8250_do_shutdown() releases the interrupt handler before the
handler has run and processed the BUSY_DETECT condition by read the USR
register, the IRQ is not deasserted resulting in interrupt storm that
triggers "irq x: nobody cared" warning leading to disabling the IRQ.
Add late synchronize_irq() into serial8250_do_shutdown() to ensure
BUSY_DETECT from DW UART is handled before port's interrupt handler is
released. Alternative would be to add DW UART specific shutdown
function but it would mostly duplicate the generic code and the extra
synchronize_irq() seems pretty harmless in serial8250_do_shutdown().
Fixes: 7d4008ebb1 ("tty: add a DesignWare 8250 driver")
Cc: stable <stable@kernel.org>
Reported-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
INTC10EE UART can end up into an interrupt storm where it reports
IIR_NO_INT (0x1). If the storm happens during active UART operation, it
is promptly stopped by IIR value change due to Rx or Tx events.
However, when there is no activity, either due to idle serial line or
due to specific circumstances such as during shutdown that writes
IER=0, there is nothing to stop the storm.
During shutdown the storm is particularly problematic because
serial8250_do_shutdown() calls synchronize_irq() that will hang in
waiting for the storm to finish which never happens.
This problem can also result in triggering a warning:
irq 45: nobody cared (try booting with the "irqpoll" option)
[...snip...]
handlers:
serial8250_interrupt
Disabling IRQ #45
Normal means to reset interrupt status by reading LSR, MSR, USR, or RX
register do not result in the UART deasserting the IRQ.
Add a quirk to INTC10EE UARTs to enable Tx interrupts if UART's Tx is
currently empty and inactive. Rework IIR_NO_INT to keep track of the
number of consecutive IIR_NO_INT, and on fourth one perform the quirk.
Enabling Tx interrupts should change IIR value from IIR_NO_INT to
IIR_THRI which has been observed to stop the storm.
Fixes: e92fad0249 ("serial: 8250_dw: Add ACPI ID for Granite Rapids-D UART")
Cc: stable <stable@kernel.org>
Reported-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dw8250_handle_irq() takes port's lock multiple times with no good
reason to release it in between and calls serial8250_handle_irq()
that also takes port's lock.
Take port's lock only once in dw8250_handle_irq() and use
serial8250_handle_irq_locked() to avoid releasing port's lock in
between.
As IIR_NO_INT check in serial8250_handle_irq() was outside of port's
lock, it has to be done already in dw8250_handle_irq().
DW UART can, in addition to IIR_NO_INT, report BUSY_DETECT (0x7) which
collided with the IIR_NO_INT (0x1) check in serial8250_handle_irq()
(because & is used instead of ==) meaning that no other work is done by
serial8250_handle_irq() during an BUSY_DETECT interrupt.
This allows reorganizing code in dw8250_handle_irq() to do both
IIR_NO_INT and BUSY_DETECT handling right at the start simplifying
the logic.
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Cc: stable <stable@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
8250_port exports serial8250_handle_irq() to HW specific 8250 drivers.
It takes port's lock within but a HW specific 8250 driver may want to
take port's lock itself, do something, and then call the generic
handler in 8250_port but to do that, the caller has to release port's
lock for no good reason.
Introduce serial8250_handle_irq_locked() which a HW specific driver can
call while already holding port's lock.
As this is new export, put it straight into a namespace (where all 8250
exports should eventually be moved).
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Cc: stable <stable@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
