SCIFA IP on RZ/G2L SoC has the same signal for both interrupt
and DMA transfer request. Setting DMARS register for DMA transfer
makes the signal to work as a DMA transfer request signal and
subsequent interrupt requests to the interrupt controller
are masked. Similarly clearing DMARS register makes signal to work as
interrupt signal and subsequent interrupt requests to the interrupt
controller are unmasked.
Add SCIFA DMA rx support for RZ/G2L alike SoCs by disabling RXI line
interrupt and setting DMARS registers by DMA api for DMA transfer request.
Apart from this, we must set FIFO trigger to 1 for the expected behavior
of the receive transmission.
While at it replace the parameter irq to s->irqs[SCIx_RXI_IRQ] in
disable_irq_nosync() to match enable_irq() in sci_dma_rx_reenable_irq().
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230412145053.114847-3-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SCIFA IP on RZ/G2L SoC has the same signal for both interrupt
and DMA transfer request. Setting DMARS register for DMA transfer
makes the signal to work as a DMA transfer request signal and
subsequent interrupt requests to the interrupt controller
are masked. Similarly clearing DMARS register makes signal to work as
interrupt signal and subsequent interrupt requests to the interrupt
controller are unmasked.
Add SCIFA DMA tx support for RZ/G2L alike SoCs by disabling TXI line
interrupt and setting DMARS registers by DMA api for DMA transfer request.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230412145053.114847-2-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After upgrading from 5.16 to 6.1, our board with a MAX14830 started
producing lots of garbage data over UART. Bisection pointed out commit
285e76fc04 as the culprit. That patch tried to replace hand-written
code which I added in 2b4bac48c1 ("serial: max310x: Use batched reads
when reasonably safe") with the generic regmap infrastructure for
batched operations.
Unfortunately, the `regmap_raw_read` and `regmap_raw_write` which were
used are actually functions which perform IO over *multiple* registers.
That's not what is needed for accessing these Tx/Rx FIFOs; the
appropriate functions are the `_noinc_` versions, not the `_raw_` ones.
Fix this regression by using `regmap_noinc_read()` and
`regmap_noinc_write()` along with the necessary `regmap_config` setup;
with this patch in place, our board communicates happily again. Since
our board uses SPI for talking to this chip, the I2C part is completely
untested.
Fixes: 285e76fc04 ("serial: max310x: use regmap methods for SPI batch operations")
Cc: stable@vger.kernel.org
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Link: https://lore.kernel.org/r/79db8e82aadb0e174bc82b9996423c3503c8fb37.1680732084.git.jan.kundrat@cesnet.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While rebinding a uart device in a loop I noticed we may see a tx related
race on uart_remove_one_port():
uart_write from n_tty_write
n_tty_write from file_tty_write.constprop.0
file_tty_write.constprop.0 from vfs_write
vfs_write from ksys_write
ksys_write from ret_fast_syscall
Let's disallow tx on port->UPF_DEAD. This flag gets set before we start
tearing down the port in uart_remove_one_port().
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230419115423.59957-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When we unbind a serial port hardware specific 8250 driver, the generic
serial8250 driver takes over the port. After that we see an oops about 10
seconds later. This can produce the following at least on some TI SoCs:
Unhandled fault: imprecise external abort (0x1406)
Internal error: : 1406 [#1] SMP ARM
Turns out that we may still have the serial port hardware specific driver
port->pm in use, and serial8250_pm() tries to call it after the port
specific driver is gone:
serial8250_pm [8250_base] from uart_change_pm+0x54/0x8c [serial_base]
uart_change_pm [serial_base] from uart_hangup+0x154/0x198 [serial_base]
uart_hangup [serial_base] from __tty_hangup.part.0+0x328/0x37c
__tty_hangup.part.0 from disassociate_ctty+0x154/0x20c
disassociate_ctty from do_exit+0x744/0xaac
do_exit from do_group_exit+0x40/0x8c
do_group_exit from __wake_up_parent+0x0/0x1c
Let's fix the issue by calling serial8250_set_defaults() in
serial8250_unregister_port(). This will set the port back to using
the serial8250 default functions, and sets the port->pm to point to
serial8250_pm.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230418101407.12403-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In synclinc_gt, the flag_buf is allocated, zeroed and passed to ldisc's
receive_buf(). It is never written to, so it serves as a dummy buffer.
That's unneeded because all ldiscs accept NULL as flags. That NULL
resolves to the TTY_NORMAL flag.
So drop all this nonsense.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230420093530.13133-1-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull tty/serial driver fixes from Greg KH:
"Here are some small tty and serial driver fixes for some reported
problems:
- fsl_uart driver bugfixes
- sh-sci serial driver bugfixes
- renesas serial driver DT binding bugfixes
- 8250 DMA bugfix
All of these have been in linux-next for a while with no reported
problems"
* tag 'tty-6.3-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
tty: serial: sh-sci: Fix Rx on RZ/G2L SCI
tty: serial: fsl_lpuart: fix crash in lpuart_uport_is_active
tty: serial: fsl_lpuart: avoid checking for transfer complete when UARTCTRL_SBK is asserted in lpuart32_tx_empty
serial: 8250: Prevent starting up DMA Rx on THRI interrupt
dt-bindings: serial: renesas,scif: Fix 4th IRQ for 4-IRQ SCIFs
tty: serial: sh-sci: Fix transmit end interrupt handler
With linux/acpi.h no longer implicitly including of.h, add an explicit
include of of.h to fix the following error:
drivers/tty/serial/8250/8250_tegra.c:68:15: error: implicit declaration of function 'of_alias_get_id' [-Werror=implicit-function-declaration]
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We need the fixes in here for testing, as well as the driver core
changes for documentation updates to build on.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
According to LPUART RM, Transmission Complete Flag becomes 0 if queuing
a break character by writing 1 to CTRL[SBK], so here need to avoid
checking for transmission complete when UARTCTRL_SBK is asserted,
otherwise the lpuart32_tx_empty may never get TIOCSER_TEMT.
Commit 2411fd94ceaa("tty: serial: fsl_lpuart: skip waiting for
transmission complete when UARTCTRL_SBK is asserted") only fix it in
lpuart32_set_termios(), here also fix it in lpuart32_tx_empty().
Fixes: 380c966c09 ("tty: serial: fsl_lpuart: add 32-bit register interface support")
Cc: stable <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20230323054415.20363-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Hans de Goede reported Bluetooth adapters (HCIs) connected over an UART
connection failed due corrupted Rx payload. The problem was narrowed
down to DMA Rx starting on UART_IIR_THRI interrupt. The problem occurs
despite LSR having DR bit set, which is precondition for attempting to
start DMA Rx in the first place.
From a debug patch:
[x.807834] 8250irq: iir=cc lsr+saved=60 received=0/15 ier=0f dma_t/rx/err=0/0/0
[x.808676] 8250irq: iir=c2 lsr+saved=61 received=0/0 ier=0f dma_t/rx/err=0/0/0
[x.808776] 8250irq: iir=cc lsr+saved=60 received=1/12 ier=0d dma_t/rx/err=0/1/0
[x.808870] Bluetooth: hci0: Frame reassembly failed (-84)
In the debug snippet, received field indicates 1 byte was transferred
over DMA and 12 bytes after that with the non-DMA Rx. The sole byte DMA
handled was corrupted (gets zeroed) which leads to the HCI failure.
This problem became apparent after commit e8ffbb71f7 ("serial: 8250:
use THRE & __stop_tx also with DMA") changed Tx stop behavior. Tx stop
is now triggered from a THRI interrupt.
Despite that this problem looks like a HW bug, this fix is not adding
UART_BUG_xx flag to the driver beucase it seems useful in general to
avoid starting DMA when there are only a few bytes to transfer.
Skipping DMA for small transfers avoids the extra overhead DMA incurs.
Thus, don't setup DMA Rx on UART_IIR_THRI but leave it to a subsequent
interrupt which has Rx a related IIR value.
By returning false from handle_rx_dma(), the DMA vs non-DMA decision is
postponed until either UART_IIR_RDI (FIFO threshold worth of bytes
awaiting) or UART_IIR_TIMEOUT (inter-character timeout) triggers at a
later time which allows better to discern whether the number of bytes
warrants starting DMA or not.
Reported-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Fixes: e8ffbb71f7 ("serial: 8250: use THRE & __stop_tx also with DMA")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230317103034.12881-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There's a potential race before THRE/TEMT deasserts when DMA Tx is
starting up (or the next batch of continuous Tx is being submitted).
This can lead to misdetecting Tx empty condition.
It is entirely normal for THRE/TEMT to be set for some time after the
DMA Tx had been setup in serial8250_tx_dma(). As Tx side is definitely
not empty at that point, it seems incorrect for serial8250_tx_empty()
claim Tx is empty.
Fix the race by also checking in serial8250_tx_empty() whether there's
DMA Tx active.
Note: This fix only addresses in-kernel race mainly to make using
TCSADRAIN/FLUSH robust. Userspace can still cause other races but they
seem userspace concurrency control problems.
Fixes: 9ee4b83e51 ("serial: 8250: Add support for dmaengine")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230317113318.31327-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If userspace races tcsetattr() with a write, the drained condition
might not be guaranteed by the kernel. There is a race window after
checking Tx is empty before tty_set_termios() takes termios_rwsem for
write. During that race window, more characters can be queued by a
racing writer.
Any ongoing transmission might produce garbage during HW's
->set_termios() call. The intent of TCSADRAIN/FLUSH seems to be
preventing such a character corruption. If those flags are set, take
tty's write lock to stop any writer before performing the lower layer
Tx empty check and wait for the pending characters to be sent (if any).
The initial wait for all-writers-done must be placed outside of tty's
write lock to avoid deadlock which makes it impossible to use
tty_wait_until_sent(). The write lock is retried if a racing write is
detected.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230317113318.31327-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The direction field in the DMA config is deprecated. The sh-sci driver
sets {src,dst}_{addr,addr_width} based on the DMA direction and
it results in dmaengine_slave_config() failure as RZ DMAC driver
validates {src,dst}_addr_width values independent of DMA direction.
Fix this issue by passing both {src,dst}_{addr,addr_width}
values independent of DMA direction.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230322074717.6057-1-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 1ea35b3557 ("ARM: s3c: remove s3c24xx specific hacks"), allows
simplifying the whole config logic for SERIAL_SAMSUNG_UARTS, and did this
config simplification. However, it misses that SERIAL_SAMSUNG_UARTS_4's
effect was just to control SERIAL_SAMSUNG_UARTS, and with the commit's
change, the config SERIAL_SAMSUNG_UARTS_4 has no remaining effect and can
be deleted.
Remove this obsolete config SERIAL_SAMSUNG_UARTS_4.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20230317071538.29366-1-lukas.bulwahn@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On sc7180 Chromebooks, I did the following:
* Didn't enable earlycon in the kernel command line.
* Didn't enable serial console in the kernel command line.
* Didn't enable an agetty or any other client of "/dev/ttyMSM0".
* Added "kgdboc=ttyMSM0" to the kernel command line.
After I did that, I tried to enter kdb with this command over an ssh
session:
echo g > /proc/sysrq-trigger
When I did that the system just hung.
Although I thought I'd tested this scenario before, I couldn't go back
and find a time when it was working. Previous testing must have relied
on either the UART acting as the kernel console or an agetty running.
It turns out to be pretty easy to fix: we can just use
qcom_geni_serial_port_setup() as the .poll_init() function. This,
together with the patch ("serial: uart_poll_init() should power on the
UART"), allows the debugger to work even if there are no other users
of the serial port.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20230316132027.RESEND.2.Ie678853bb101091afe78cc8c22344bf3ff3aed74@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The application which initializes the n_gsm ldisc may like to set
individual default parameters for each DLCI or take over of the application
specific DLCI configuration completely. This is currently not possible.
It is either possible to set common default parameters for all DLCIs or let
the user application set its DLCI specific configuration parameters.
Add support of GSMIOC_GETCONF_DLCI and GSMIOC_SETCONF_DLCI for the n_gsm
ldisc handle to support DLCI specific parameter configuration upfront.
Add a code example for this use case to the n_gsm documentation.
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20230315105354.6234-3-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 6 describes the error recovery mode option
which is based on I frames. The k parameter defines the maximum number of
I frames that a DLC can have unacknowledged as described in chapter 5.7.4.
The current n_gsm implementation does not support the error recovery mode
option. However, the k parameter is also part of the parameter negotiation
message as described in chapter 5.4.6.3.1. Chapter 5.7.4 also notes that
the allowed value range for k is 1-7. That means a 0 is counted as invalid
here. This means that the user needs to configure a valid value here even
if the function itself is not supported. Otherwise, parameter negotiation
may fail.
Allow setting of k via ioctl in gsm_config(). Range checks are already
included.
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20230315105354.6234-2-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Parameter negotiation has been introduced with
commit 92f1f0c329 ("tty: n_gsm: add parameter negotiation support")
However, means to set individual parameters per DLCI are not yet
implemented. Furthermore, it is currently not possible to keep a DLCI half
open until the user application sets the right parameters for it. This is
required to allow a user application to set its specific parameters before
the underlying link is established. Otherwise, the link is opened and
re-established right afterwards if the user application sets incompatible
parameters. This may be an unexpected behavior for the peer.
Add parameter 'wait_config' to 'gsm_config' to support setups where the
DLCI specific user application sets its specific parameters after open()
and before the link gets fully established. Setting this to zero disables
the user application specific DLCI configuration option.
Add the ioctls 'GSMIOC_GETCONF_DLCI' and 'GSMIOC_SETCONF_DLCI' for the
ldisc and virtual ttys. This gets/sets the DLCI specific parameters and may
trigger a reconnect of the DLCI if incompatible values have been set. Only
the parameters for the DLCI associated with the virtual tty can be set or
retrieved if called on these.
Add remark within the documentation to introduce the new ioctls.
Link: https://lore.kernel.org/oe-kbuild-all/202302281856.S9Lz4gHB-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20230315105354.6234-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull xen fixes from Juergen Gross:
- fix build warning
- avoid concurrent accesses to the Xen PV console ring page
* tag 'for-linus-6.3-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
x86/PVH: avoid 32-bit build warning when obtaining VGA console info
hvc/xen: prevent concurrent accesses to the shared ring
The hvc machinery registers both a console and a tty device based on
the hv ops provided by the specific implementation. Those two
interfaces however have different locks, and there's no single locks
that's shared between the tty and the console implementations, hence
the driver needs to protect itself against concurrent accesses.
Otherwise concurrent calls using the split interfaces are likely to
corrupt the ring indexes, leaving the console unusable.
Introduce a lock to xencons_info to serialize accesses to the shared
ring. This is only required when using the shared memory console,
concurrent accesses to the hypercall based console implementation are
not an issue.
Note the conditional logic in domU_read_console() is slightly modified
so the notify_daemon() call can be done outside of the locked region:
it's an hypercall and there's no need for it to be done with the lock
held.
Fixes: b536b4b962 ('xen: use the hvc console infrastructure for Xen console')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20221130150919.13935-1-roger.pau@citrix.com
Signed-off-by: Juergen Gross <jgross@suse.com>
We need the tty/serial fixes in here and it resolves a merge conflict
with:
drivers/tty/serial/8250/8250_em.c
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We need the mainline fixes in this branch for testing and other
subsystem changes to be based properly on.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull tty/serial driver fixes from Greg KH:
"Here are some small tty and serial driver fixes for 6.3-rc3 to resolve
some reported issues.
They include:
- 8250 driver Kconfig issue pointed out by you that showed up in -rc1
- qcom-geni serial driver fixes
- various 8250 driver fixes for reported problems
- fsl_lpuart driver fixes
- serdev fix for regression in -rc1
- vt.c bugfix
All have been in linux-next for over a week with no reported problems"
* tag 'tty-6.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
tty: vt: protect KD_FONT_OP_GET_TALL from unbound access
serial: qcom-geni: drop bogus uart_write_wakeup()
serial: qcom-geni: fix mapping of empty DMA buffer
serial: qcom-geni: fix DMA mapping leak on shutdown
serial: qcom-geni: fix console shutdown hang
serdev: Set fwnode for serdev devices
tty: serial: fsl_lpuart: fix race on RX DMA shutdown
serial: 8250_pci1xxxx: Disable SERIAL_8250_PCI1XXXX config by default
serial: 8250_fsl: fix handle_irq locking
serial: 8250_em: Fix UART port type
serial: 8250: ASPEED_VUART: select REGMAP instead of depending on it
tty: serial: fsl_lpuart: skip waiting for transmission complete when UARTCTRL_SBK is asserted
Revert "tty: serial: fsl_lpuart: adjust SERIAL_FSL_LPUART_CONSOLE config dependency"
The arbitration of the UART DMA is mishandled for a few
exceptional cases when probing and releasing the driver.
It is possible that the DMA register spaces are not defined in
device tree for an instance of the driver, so attempts to access
the registers in brcmuart_arbitration() would use NULL pointers.
It is also possible for the probe function to return an error
while still holding the UART DMA. This would prevent the UART
DMA from being claimed by an instance that could use it.
These errors are addressed by only releasing the UART DMA if it
is held by this instance (i.e. priv->dma_enabled == 1) and
directing early error paths in probe to this common release_dma
handling.
Fixes: 41a469482d ("serial: 8250: Add new 8250-core based Broadcom STB driver")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20230309190224.687380-1-opendmb@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When PARMRK is set, a character can result in up to 3 chars in the read
buffer. Receive code calculates for how many characters there (at
least) is room. Convert an opencoded rounding in the calculation to use
DIV_ROUND_UP().
Note: the room variable is decremented afterwards by one which ensures
the characters will fit into the buffer for real so the code is okay
despite rounding upwards.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230309082035.14880-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
