The rvgen code generator needs validation to ensure it produces correct
monitor implementations from input specifications.
Add selftests with golden reference outputs covering all monitor classes
(DA, HA, LTL) and types (global, per_cpu, per_task, per_obj), including
optional features like descriptions and parent monitors. Container
generation and error handling (missing files, invalid specifications,
missing arguments) are also validated against expected output.
Acked-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Wen Yang <wen.yang@linux.dev>
Link: https://lore.kernel.org/r/20260723074534.43521-9-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The rv tool needs automated testing to catch regressions and verify
correct functionality across different usage scenarios.
Add selftests that validate monitor listing (including containers and
nested monitors), monitor execution with different configurations
(reactors, verbose output, tracing), and trace output format for both
per-task and per-cpu monitors. Error handling paths are also tested.
Tests use a shared engine for common patterns.
Acked-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260723074534.43521-7-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Template files for rvgen had minor inconsistencies in their
placeholders for default author and default tracepoint examples. The
user needs to modify those anyway but keeping consistency may help in
bulk editing or checking.
Change default author from "dot2k: auto-generated" (for DA/containers)
or /* TODO */ (for LTL) to the general "rvgen: auto-generated".
Align the sample tracepoint handler name in LTL template to
handle_example_event, consistently with the rest of the file.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260723074534.43521-6-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The RVGenerator class can find the RV directory (kernel/trace/rv) in the
kernel tree to do some auto patching. This works by assuming PWD is
either the kernel tree or tools/verification, which isn't always the
case (e.g. when running from selftests).
Make discovery more robust by relying on the absolute path of the
current script and traversing backwards the right number of times.
This should work from any location if rvgen is in the kernel tree.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260723074534.43521-4-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
When running "rv mon" on a monitor that is already enabled, the tool
fails to start but incorrectly exits with a success status (0).
Fix the exit condition to ensure it returns a failure code on any
execution error. Also use the standard EXIT_SUCCESS/EXIT_FAILURE macros
throughout the file.
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260723074534.43521-3-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Add a wakeup monitor to detect a lower-priority task waking up a
higher-priority task.
The rtapp/sleep monitor already detects this. However, that monitor
triggers an error in the context of the wakee task and user only gets
the stacktrace of that task. It is also extremely useful to get the
stacktrace of the waker task, which this monitor offers. In other
words, this monitor complements the rtapp/sleep monitor.
Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/ba5658fa13e49ada466b84a2c211f233037180b5.1781852967.git.namcao@linutronix.de
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The rtapp/sleep monitor's primary purpose is detecting common mistakes
with user-space real-time design. Monitoring real-time issues with
kernel threads is a bonus.
However, accomodating kernel threads complicates the monitor due to
the edge cases which is seen by the monitor as lower-priority task
waking higher-priority task:
- kthread_stop() wakes up the task in order to stop it.
- The rcu thread and migration thread can be woken by any task.
- The ktimerd thread is woken near the end of irq_exit_rcu(), where
the preempt counter is "broken" and falsely says this is task
context. This requires the monitor to use the hardirq_context flag
instead of the preempt counter.
Beside complicating the monitor, the final case also requires enabling
CONFIG_TRACE_IRQFLAGS (so that "hardirq_context" can be used). This
adds overhead to the kernel even when the monitor is not active. This
may be an obstacle to enabling this monitor in distros' kernels.
Furthermore, kernel threads usually are started before the monitor is
enabled. Consequently, the threads' states (i.o.w. the monitor's
atomic propositions for the threads) are not fully known to the
monitor. As a result, the kernel threads mostly cannot be monitored.
Overall, the downsides of accomodating kernel threads outweights the
benefits. Thus, exclude kernel threads to simplify the monitor.
Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/eec2ca5224bcdacc45b8e1eb2f0e68109e1cae7a.1781852967.git.namcao@linutronix.de
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The rtapp/sleep monitor detects real-time tasks which go to sleep in an
real-time-unsafe manner. If this happen, the monitor triggers a trace event
in the sched_wakeup tracepoint's handler.
However, the invoking context of that trace event is not the most
informative, because of the stack trace of that event is the wakeup's code
path which is not very helpful:
74.669317: rv:error_sleep: condvar[254]: violation detected
ltl_validate+0x345 ([kernel.kallsyms])
handle_sched_wakeup+0x34 ([kernel.kallsyms])
ttwu_do_activate+0xff ([kernel.kallsyms])
sched_ttwu_pending+0x104 ([kernel.kallsyms])
__flush_smp_call_function_queue+0x15b ([kernel.kallsyms])
__sysvec_call_function_single+0x18 ([kernel.kallsyms])
sysvec_call_function_single+0x66 ([kernel.kallsyms])
asm_sysvec_call_function_single+0x1a ([kernel.kallsyms])
pv_native_safe_halt+0xf ([kernel.kallsyms])
default_idle+0x9 ([kernel.kallsyms])
default_idle_call+0x33 ([kernel.kallsyms])
do_idle+0x234 ([kernel.kallsyms])
cpu_startup_entry+0x24 ([kernel.kallsyms])
start_secondary+0xf8 ([kernel.kallsyms])
common_startup_64+0x13e ([kernel.kallsyms])
What would be much more valuable is the stack trace of the task itself.
Instead of using the sched_wakeup tracepoint, use the sched_exit
tracepoint. This makes the event happen in the task's context, making
the stack trace far more informative for user:
rv:error_sleep: condvar[254]: violation detected
ltl_validate+0x345 ([kernel.kallsyms])
handle_sched_exit+0x39 ([kernel.kallsyms])
__schedule+0x80f ([kernel.kallsyms])
schedule+0x22 ([kernel.kallsyms])
futex_do_wait+0x33 ([kernel.kallsyms])
__futex_wait+0x8c ([kernel.kallsyms])
futex_wait+0x73 ([kernel.kallsyms])
do_futex+0xc6 ([kernel.kallsyms])
__x64_sys_futex+0x121 ([kernel.kallsyms])
do_syscall_64+0xf3 ([kernel.kallsyms])
entry_SYSCALL_64_after_hwframe+0x77 ([kernel.kallsyms])
__futex_abstimed_wait_common64+0xc6 (inlined)
__futex_abstimed_wait_common+0xc6 (/usr/lib/x86_64-linux-gnu/libc.so.6)
Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/d97b4b5c476e5792b6875ec9bbf8dc214f999516.1781852967.git.namcao@linutronix.de
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The slot array already tracks allocation and task_monitor_count
duplicates that state. On an invalid second release, the old code
warns but still decrements the counter, corrupting later allocations.
Use the slot array as the sole source of truth. Return after warning
about an unused slot, and return -EBUSY when no slot is free.
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
Link: https://lore.kernel.org/r/20260715015825.1413822-1-liqiang01@kylinos.cn
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Per-object monitors can allocate memory dynamically and such memory is
required for the lifetime of the object, then it should be freed with
the appropriate call.
Force the generation scripts to add a cleanup function the user will
need to wire to the appropriate event (e.g. sched_process_exit for
tasks). This can be safely removed if the object will never cease to
exist before disabling the monitor (e.g. if following only static
variables).
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260601153840.124372-14-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The da_monitor_reset_all() function for per-task monitors takes
tasklist_lock while iterating over tasks, then keeps it also while
iterating over idle tasks (one per CPU). The latter is not necessary
since the lock needs to guard only for_each_process_thread().
Use a scoped_guard for more compact syntax and adjust the scope only
where the lock is necessary.
Reviewed-by: Wen Yang <wen.yang@linux.dev>
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260601153840.124372-13-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Hybrid automata monitors's clock variables have two different
representations:
- The invariant representation, which is the timestamp when the invariant
expires
- The guard representation, which is the timestamp when the clock is last
reset
This dual representation makes the logic quite difficult to follow (well,
at least for me). It also complicates the monitors and the generation tool,
as it requires conversion back and forth between the representation.
Simplify by using the clock variables for a single purpose: storing the
time stamp since the clock is last reset.
This also allows simplifying rvgen, which will be done in a follow-up
commit.
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/c0f600dcbf3d8b487c944406851a39146f4d91fa.1781847583.git.namcao@linutronix.de
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The DOT parsing scripts directly parse the raw text and they are quite
fragile. If the input dot files' formats are slightly changed (for
instance, by breaking long some lines which is allowed by the DOT
language), the scripts would fail.
Prepare to move away from the raw text processing, implement parsers based
on Lark which parse states, transitions and constraints.
The parse results are not used yet. The existing scripts will be converted
one by one to them, and the raw text processing will eventually be removed.
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/3ef60fdb03154abb9d9718ea106484213e1a4598.1781847583.git.namcao@linutronix.de
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
The DOT parsing scripts directly parse the raw text and they are quite
fragile. If the input dot files' formats are slightly changed (for
instance, by breaking long some lines which is allowed by the DOT language
defined by graphviz), the scripts would fail.
To make the scripts robust, the parser should be implemented based on the
dot language specification, not based on how the existing dot files look.
As a first step, use Lark to implement a Parser based on the graphviz dot
language specification. The resulting parse tree is not used yet, but the
existing scripts will be converted one by one to use this new parse tree in
the follow-up commits.
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/f816bce4cc7c48d0b6b6a28a7029459df69d6a71.1781847583.git.namcao@linutronix.de
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Pull RISC-V fixes from Paul Walmsley:
- Call flush_cache_vmap() after populating new vmemmap pages, on all
architectures. This avoids spurious faults on RISC-V
microarchitectures that cache PTEs marked as non-present
- Disable LTO for the vDSO to prevent the compiler from eliding
functions that are used, but which don't appear to be
- Fix an issue with libgcc's unwinder and signal handlers by dropping
an unnecessary CFI landing pad instruction in __vdso_rt_sigreturn
(similar to what was done on ARM64)
- Avoid reading uninitialized memory under certain conditions in
hwprobe_get_cpus()
- Save some memory and I$ when CONFIG_DYNAMIC_FTRACE=n by avoiding our
four-byte function alignment requirement in that case
- Avoid clang warnings about null-pointer arithmetic in the I/O-port
accessor macros (inb, outb, etc.) by ifdeffing them out when
!CONFIG_HAS_IOPORT
- Make the build of the lazy TLB flushing code in the vmalloc path
depend on CONFIG_64BIT and CONFIG_MMU (since those platforms are the
only ones that use it)
* tag 'riscv-for-linus-7.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: hwprobe: Avoid uninitialized read in hwprobe_get_cpus()
arch/riscv: vdso: remove CFI landing pad from rt_sigreturn
riscv: vdso: Do not use LTO for the vDSO
riscv: io: avoid null-pointer arithmetic in PIO helpers
riscv: Gate FUNCTION_ALIGNMENT_4B on DYNAMIC_FTRACE
mm/sparse-vmemmap: flush_cache_vmap() after hotplugging vmemmap
riscv: mm: Make mark_new_valid_map() stuff depend on 64BIT && MMU
Pull block fixes from Jens Axboe:
- Fixes for the dio bounce buffer helpers: correct the alignment of
bounced dio read bios to avoid a double unpin, handle huge zero
folios in bio_free_folios(), and don't warn on the larger-order folio
attempts in the greedy allocation path.
- Try a slab allocation in bio_alloc_bioset() before falling back to
the mempool, restoring the previous behavior for non-sleeping
allocations from a cache-enabled bioset.
- Serialize elevator changes for the same queue using the writer lock.
- Fix a race in blk_time_get_ns() where a task preempted between
setting PF_BLOCK_TS and the cached-timestamp reload could return 0.
- blk-cgroup fix for leaks and the online flag on a radix_tree_insert()
failure in blkg_create().
- Free the copied pages when blk_rq_map_kern() fails after
blk_rq_append_bio() rejects the bio.
- Remove manually added partitions on loop device detach, fixing dead
partition devices left behind and a subsequent LOOP_CONFIGURE -EBUSY
- Bound the AIX partition lvd scan to the sector that was actually
read.
- Show the block operation in error injection rules (Jackie)
* tag 'block-7.2-20260717' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
block: fix aligning of bounced dio read bios
block: handle huge zero folios in bio_free_folios
block: try slab allocation in bio_alloc_bioset() before mempool
block: show operation in error injection rules
block: serialize elevator changes for the same queue using a writer lock
block: free copied pages when blk_rq_map_kern() fails
block: do not warn when doing greedy allocation in folio_alloc_greedy()
partitions: aix: bound the lvd scan to one sector
blk-cgroup: fix leaks and online flag on radix_tree_insert failure
loop: remove manually added partitions on detach
block: fix race in blk_time_get_ns() returning 0
Pull io_uring fixes from Jens Axboe:
- Fix a use-after-free in the bpf-ops struct_ops path, where the same
io_uring_bpf_ops map could be registered more than once.
- Fix the deferred iovec free for the provided-buffer grow path, which
could leave the caller with a dangling iovec and result in repeated
frees. Follow-up to the earlier fix in this series.
- Zero-check the unused addr3/pad2 SQE fields for unlinkat
* tag 'io_uring-7.2-20260717' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
io_uring/bpf-ops: reject re-registration of an already-bound ops
io_uring/fs: check unused sqe fields for unlinkat
io_uring/kbuf: free the replaced iovec after a successful grow
Pull spi fixes from Mark Brown:
"A couple of fairly routine driver fixes, nothing too remarkable"
* tag 'spi-fix-v7.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: cadence-quadspi: Fix indirect write timeout when DMA read mode is enabled
spi: dw-dma: Wait for controller idle before completing Tx
Pull regulator fix from Mark Brown:
"One straightforward driver fix for some incorrectly described
bitfields in the ltc3676 driver"
* tag 'regulator-fix-v7.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: ltc3676: Fix incorrect IRQSTAT bit offsets
Pull x86 fixes from Ingo Molnar:
- Reject too long acpi_rsdp= boot parameter values (Thorsten Blum)
- Validate console=uart8250 baud rate to fix early boot hang (Thorsten
Blum)
- Remove dead Makefile rule (Ethan Nelson-Moore)
* tag 'x86-urgent-2026-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot: Validate console=uart8250 baud rate to fix early boot hang
x86/boot: Reject too long acpi_rsdp= values
x86/cpu: Remove Makefile rule for removed UMC CPU support
Pull s390 fixes from Vasily Gorbik:
- Fix checksum lib on machines without the vector facility where the
non-vector fallback made csum_partial() calculate the checksum from
address 0 instead of the provided buffer
- Fix cpum_cf perf event initialization missing speculation barrier for
user controlled event numbers used as generic event array indexes
* tag 's390-7.2-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/perf_cpum_cf: Add missing array_index_nospec() to __hw_perf_event_init()
s390/checksum: Fix csum_partial() without vector facility
Pull ARC fixes from Vineet Gupta:
- Misc fixes and config updates
* tag 'arc-7.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: configs: Drop redundant I2C_DESIGNWARE_PLATFORM
arc: validate DT CPU map strings before parsing them
Pull SCSI fixes from James Bottomley:
"The biggest core change is the reliable wake fix for scsi_schedule_eh
which is used by both libata and libsas which could otherwise cause
error handler hangs due to rare races.
All other fixes are in drivers (well except the export symbol removal)
the next biggest being the target PR-OUT transportid parsing fix"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: hpsa: Fix DMA mapping leak on IOACCEL2 reset path
scsi: elx: efct: Fix refcount leak in efct_hw_io_abort()
scsi: elx: efct: Fix I/O leak on unsupported additional CDB
scsi: core: wake eh reliably when using scsi_schedule_eh
scsi: target: core: Fix iSCSI ISID use-after-free in REGISTER AND MOVE
scsi: target: Bound PR-OUT TransportID parsing to the received buffer
scsi: lpfc: Fix memory leak in lpfc_sli4_driver_resource_setup()
scsi: sg: Report request-table problems when any status is set
scsi: ufs: core: tracing: Do not dereference pointers in TP_printk()
scsi: bfa: Reduce kernel stack usage in bfa_fcs_lport_fdmi_build_portattr_block()
scsi: xen: scsiback: Free the command tag on the TMR submit-failure path
scsi: xen: scsiback: Free unsubmitted command instead of double-putting it
scsi: core: Remove export for scsi_device_from_queue()
Pull i2c fixes from Andi Shyti:
"A handful of small fixes for host controller drivers.
One patch also adds Wolfram Sang to CREDITS after more than a decade
of work on I2C"
* tag 'i2c-fixes-7.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux:
i2c: mediatek: fix WRRD for SoCs without auto_restart option
i2c: mlxbf: Fix use-after-free in mlxbf_i2c_init_resource()
i2c: spacemit: fix spurious IRQ handling returning IRQ_HANDLED
i2c: imx: fix locked bus on SMBus block-read of 0 (IRQ)
i2c: imx: fix locked bus on SMBus block-read of 0 (atomic)
CREDITS: Add Wolfram Sang
Pull smb server fixes from Steve French:
"ksmbd server fixes, mostly addressing malformed SMB request
handling and connection/session lifetime issues, including
two information-disclosure or memory-safety bugs in the SMB2
request/response paths.
- validate FILE_ALLOCATION_INFORMATION before block rounding to
prevent a client-controlled overflow from truncating a file.
- pin connections while asynchronous oplock and lease-break
notifications are pending.
- initialize compound SMB2 READ alignment padding, preventing
disclosure of uninitialized heap bytes.
- release the allocated alternate-stream xattr name after rename.
- size multichannel binding session-key buffers for the largest
permitted key, avoiding a stack buffer overflow.
- remove a disconnecting connection's channels from every session,
including channels whose binding state has since changed.
- serialize binding preauthentication-session lookup and update
against its teardown.
- check that every compound request element contains StructureSize2
before reading it"
* tag 'v7.2-rc3-smb3-server-fixes' of git://git.samba.org/ksmbd:
ksmbd: validate compound request size before reading StructureSize2
ksmbd: lock the binding preauth session in smb3_preauth_hash_rsp
ksmbd: remove stale channels from all sessions on teardown
ksmbd: fix stack buffer overflow in multichannel session-key copy
ksmbd: fix memory leak of xattr_stream_name in smb2_rename()
ksmbd: zero the smb2_read alignment tail to avoid an infoleak
ksmbd: pin conn during async oplock break notification
ksmbd: fix integer overflow in set_file_allocation_info()
Pull ata fixes from Damien Le Moal:
- Interrupt initialization and handling fixes for the Designware
ahci_dwc driver (Rosen)
- Avoid possible infinite loop when scanning completion in the
Designware ahci_dwc driver (Rosen)
* tag 'ata-7.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux:
ata: sata_dwc_460ex: fix infinite loop in NCQ tag completion bit-scanning
ata: sata_dwc_460ex: fix clear_interrupt_bit() clearing all pending interrupts
ata: sata_dwc_460ex: use platform_get_irq()
ata: sata_dwc_460ex: enable SATA interrupts only after IRQ handler is registered
[Why]
After unifying DCN interrupt sources under VUPDATE_NO_LOCK, we have two
remaining issues to clean up:
1. On DCN, flip completion is now delivered from VUPDATE_NO_LOCK
(dm_crtc_high_irq_handler) instead of GRPH_PFLIP. But VUPDATE_NO_LOCK
fires every frame, regardless of whether a flip has latched.
2. There is a window during commit where a flip is armed (pflip_status =
SUBMITTED) but not yet programmed into HW. If the VUPDATE_NO_LOCK
fires in that window, its handler would deliver a flip event to
userspace before HW has latched to it. If userspace then renders to
what it believes is now the back buffer (but HW is still latched to
it!), it will cause display corruption. This issue seemed to have
been introduced by:
commit 1159898a88 ("drm/amd/display: Handle commit plane with no FB.")
Enabling replay or psr extended the duration of this window, and
hence made corruption more likely to be observed.
[How]
* Move acrtc->event/pflip_status arming to after
update_planes_and_stream_adapter() has programmed the flip into HW.
This closes the window where pflip_status is SUBMITTED but the flip is
not yet programmed.
* Add dc_get_flip_pending_on_otg(), which reads the HUBP flip-pending
status straight from HW for the pipe(s) bound to an OTG instance. It
is keyed only by otg_inst and does not take or mutate a
dc_plane_state, so it is safe to call from the OTG interrupt handler
without racing a concurrent commit that may be modifying plane state.
* Optimistically query for flip-pending after programming, in the event
that HW latched to the new fb between programming start and arming
event. If it latched, send the vblank event immediately, rather than
wait for the next vblank IRQ.
* In the VUPDATE_NO_LOCK handler, only deliver flip completion once
dc_get_flip_pending_on_otg() reports the flip is no longer pending.
Otherwise leave the flip armed and retry on the next vupdate.
* For DCE, maintain the existing behavior of arming flips before
programming, and relying on GRPH_FLIP to fire at HW latch.
v2:
* Drop flip_programmed completion object, instead move
event/pflip_status arming after programming.
* For DCN, optimistically query for flip pending immediately after
programming, and if it latched, send event right away.
v3:
* Fix event timestamps on optimistic flip latch detection, where it's
possible for it to run *before* the vupdate IRQ updates the timestamp.
* Add more docstrings for DCN vblank handling.
* Clean up if conditions in dm_arm_vblank_event().
* Code style cleanup on braces surrounding multi-line statements.
Fixes: 9b47278cec ("drm/amd/display: temp w/a for dGPU to enter idle optimizations")
Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/3787
Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/4141
Assisted-by: Copilot:claude-opus-4.8
Tested-by: Mario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit f64a9be565)
Cc: stable@vger.kernel.org # 8382cd2349: drm/amd/display: consolidate DCN vblank/flip handling onto vupdate_no_lock
Cc: stable@vger.kernel.org
[Why]
On DCN, vblank events were delivered from VSTARTUP/VUPDATE
(dm_crtc_high_irq/dm_vupdate_high_irq) and pageflip completion from
GRPH_PFLIP (dm_pflip_high_irq). These signals can be masked by hardware
by a few things:
* DPG - DCN can Dynamically Power Gate parts of the display pipe when a
self-refresh capable eDP is connected. DPG is engaged when there's
enough static frames (detected through drm_vblank_off). Once gated,
even though the OTG (output timing generator) is still enabled,
VSTARTUP and GRPH_FLIP are masked.
* GSL - Driver can use the Global Sync Lock to block HW from latching
onto double-buffered registers during programming, to prevent HW from
latching onto a partially programmed state. This will mask VSTARTUP,
GRPH_FLIP, and VUPDATE. See dcn20_pipe_control_lock().
* MALL - A DCN accessible cache introduced in DCN32+ DGPUs that can
store fb data to allow for longer DRAM sleep. When scanning out from
MALL, VSTARTUP is masked.
When masked, events are never delivered, which can show up as flip_done
timeouts in the wild.
However, there is an interrupt source on DCN that is never masked:
VUPDATE_NO_LOCK. It's simply an unmasked variant of VUPDATE, which fires
while the OTG is active, at the exact point hardware latches
double-buffered registers. It is therefore the natural single signal for
delivering both vblank and flip-completion events on DCN, and the
correct point to timestamp both VRR and non-VRR vblanks.
DCE's interrupt sources are different, it does not have an unmaskable
VUPDATE_NO_LOCK. The only unmaskable DCE interrupt is VLINE0, but it can
only be programmed as a vline offset from vsync_start, making it
unsuitable for VRR. Thus, we keep DCE untouched and use the existing mix
of interrupt sources.
[How]
For DCN1 and newer only:
* Factor the body of dm_crtc_high_irq() into dm_crtc_high_irq_handler()
and drive it from dm_vupdate_high_irq() (VUPDATE_NO_LOCK). DCE keeps
using dm_crtc_high_irq() (VSTARTUP) and dm_pflip_high_irq()
(GRPH_PFLIP) unchanged.
* Stop registering VSTARTUP (crtc_irq) and GRPH_PFLIP (pageflip_irq) on
DCN, and stop enabling them in amdgpu_dm_crtc_set_vblank() /
manage_dm_interrupts(). Enable VUPDATE whenever vblank is enabled on
DCN (previously only in VRR mode). The secure-display vline0 interrupt
is left untouched.
* VUPDATE_NO_LOCK does not early-fire on an immediate (tearing / async)
flip, since HW latches the new address right away. Deliver the flip
completion event immediately after programming such flips in
amdgpu_dm_commit_planes(), and clear pflip_status so the next vupdate
handler does not double-send.
v2: Do not gate VUPDATE_NO_LOCK on DCN in dm_handle_vrr_transition()
Also toggle VUPDATE_NO_LOCK on DCN in dm_gpureset_toggle_interrupts()
Re-cook vblank event count and timestamp for immediate flips
Fixes: 9b47278cec ("drm/amd/display: temp w/a for dGPU to enter idle optimizations")
Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/3787
Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/4141
Assisted-by: Copilot:claude-opus-4.8
Co-developed-by: Matthew Schwartz <matthew.schwartz@linux.dev>
Signed-off-by: Matthew Schwartz <matthew.schwartz@linux.dev>
Tested-by: Mario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit c87e6635d2)
Cc: stable@vger.kernel.org
Some AMD APU multi-function devices expose an integrated USB xHCI
controller. In some circumstances (such as larger VRAM), the PM core
can resume can fail when the xHCI controller is resuming in parallel
with the GPU/display function.
On affected systems, the xHCI controller can complete pci_pm_resume
and start resuming USB devices while the GPU is still in its much
longer resume path. This race condition leads to USB device resume
failures followed by:
xhci_hcd ...: xHCI host not responding to stop endpoint command
xhci_hcd ...: HC died; cleaning up
Create a device link from any xHCI controller sharing the same PCIe
root port as the APU display function. The link uses DL_FLAG_STATELESS
and DL_FLAG_PM_RUNTIME to ensure the GPU completes its resume before
the xHCI controller begins resuming USB devices.
This device link is done specifically in amdgpu so that if the
platform firmware has been modified such that this issue doesn't happen
the version can be detected and the workaround skipped.
Suggested-by: Aaron Ma <aaron.ma@canonical.com>
Reported-by: mrh@frame.work
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221073
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Tested-by: Alexander F <superveridical@gmail.com>
Tested-by: Francis DB <francisdb@gmail.com>
Link: https://patch.msgid.link/20260713195313.1739762-1-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 07c93d7eeb)
Cc: stable@vger.kernel.org
DCN42B enables DML2 and DML21 by default and defines
dcn42b_prepare_mcache_programming(), but the resource function table only
wires the callback when CONFIG_DRM_AMD_DC_DML21 is defined.
There is no in-tree Kconfig symbol named DRM_AMD_DC_DML21, so the
preprocessor always removes the callback entry. Sibling DCN42 and DCN401
resource tables wire their prepare_mcache_programming callbacks
unconditionally, and the core DC code already checks whether the callback
pointer is present before calling it.
Remove the stale guard so DCN42B exposes the callback relation that its
source and DML21 build world already provide.
This is an RFC patch draft from static conditional callback legality
auditing. It needs AMD display maintainer review before submission as a
final fix.
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Reviewed-by: George Zhang <george.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 85453fb4ff)
In dm_update_crtc_state(), the skip_modeset path releases new_stream
via dc_stream_release() but does not set the pointer to NULL.
If a later error (e.g., color management failure) triggers the fail
label, the error path calls dc_stream_release() again on the same
dangling pointer, causing a double release and potential use-after-free.
Fix this by setting new_stream to NULL after the initial release.
Fixes: 9b690ef3c7 ("drm/amd/display: Avoid full modeset when not required")
Signed-off-by: WenTao Liang <vulab@iscas.ac.cn>
Reviewed-by: George Zhang <george.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 99f3af1907)
Cc: stable@vger.kernel.org
