When using page list framebuffer, and using RGB888 format, some
pixels can cross the page boundaries, and this case was not handled,
leading to writing 1 or 2 bytes on the next virtual address.
Add a check and a specific function to handle this case.
Fixes: c9ff280879 ("drm/panic: Add support to scanout buffer as array of pages")
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20251009122955.562888-7-jfalempe@redhat.com
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
In the unlikely case that the screen is tiny, and smaller than the
font width, it leads to a divide by 0:
draw_line_with_wrap()
chars_per_row = sb->width / font->width = 0
line_wrap.len = line->len % chars_per_row;
This will trigger a divide by 0
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20251009122955.562888-6-jfalempe@redhat.com
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
The madvise implementation currently resets the SVM madvise if the
underlying CPU map is unmapped. This is in an attempt to mimic the
CPU madvise behaviour. However, it's not clear that this is a desired
behaviour since if the end app user relies on it for malloc()ed
objects or stack objects, it may not work as intended.
Instead of having the autoreset functionality being a direct
application-facing implicit UAPI, make the UMD explicitly choose
this behaviour if it wants to expose it by introducing
DRM_XE_VM_BIND_FLAG_MADVISE_AUTORESET, and add a semantics
description.
v2:
- Kerneldoc fixes. Fix a commit log message.
Fixes: a2eb8aec3e ("drm/xe: Reset VMA attributes to default in SVM garbage collector")
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Cc: "Falkowski, John" <john.falkowski@intel.com>
Cc: "Mrozek, Michal" <michal.mrozek@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Link: https://lore.kernel.org/r/20251015170726.178685-2-thomas.hellstrom@linux.intel.com
(cherry picked from commit 59a2d3f38a)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
When splitting and restoring vmas for madvise, we only copied the
XE_VMA_SYSTEM_ALLOCATOR flag. That meant we lost flags for read_only,
dumpable and sparse (in case anyone would call madvise for the latter).
Instead, define a mask of relevant flags and ensure all are replicated,
To simplify this and make the code a bit less fragile, remove the
conversion to VMA_CREATE flags and instead just pass around the
gpuva flags after initial conversion from user-space.
Fixes: a2eb8aec3e ("drm/xe: Reset VMA attributes to default in SVM garbage collector")
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20251015170726.178685-1-thomas.hellstrom@linux.intel.com
(cherry picked from commit b3af8658ec)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Separating the panic allocation from framebuffer allocation in commit
729c5f7ffa ("drm/{i915,xe}/panic: move framebuffer allocation where it
belongs") failed to deallocate the panic structure anywhere.
The fix is two-fold. First, free the panic structure in
intel_user_framebuffer_destroy() in the general case. Second, move the
panic allocation later to intel_framebuffer_init() to not leak the panic
structure in error paths (if any, now or later) between
intel_framebuffer_alloc() and intel_framebuffer_init().
v2: Rebase
Fixes: 729c5f7ffa ("drm/{i915,xe}/panic: move framebuffer allocation where it belongs")
Cc: Jocelyn Falempe <jfalempe@redhat.com>
Cc: Maarten Lankhorst <dev@lankhorst.se>
Reported-by: Michał Grzelak <michal.grzelak@intel.com>
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Michał Grzelak <michal.grzelak@intel.com> # v1
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20251015095135.2183415-1-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
(cherry picked from commit 8f8ef09fcf)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Driver Changes:
- Increase global invalidation timeout to handle some workloads
(Kenneth Graunke)
- Fix NPD while evicting BOs in an array of VM binds (Matthew Brost)
- Fix resizable BAR to account for possibly needing to move BARs other
than the LMEMBAR (Lucas De Marchi)
- Fix error handling in xe_migrate_init() (Thomas Hellström)
- Fix atomic fault handling with mixed mappings or if the page is
already in VRAM (Matthew Brost)
- Enable media samplers power gating for platforms before Xe2 (Vinay
Belgaumkar)
- Fix de-registering exec queue from GuC when unbinding (Matthew Brost)
- Ensure data migration to system if indicated by madvise with SVM
(Thomas Hellström)
- Fix kerneldoc for kunit change (Matt Roper)
- Always account for cacheline alignment on migration (Matthew Auld)
- Drop bogus assertion on eviction (Matthew Auld)
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/rch735eqkmprfyutk3ux2fsqa3e5ve4p77w7a5j66qdpgyquxr@ao3wzcqtpn6s
amd-drm-fixes-6.18-2025-10-16:
amdgpu:
- Backlight fix
- SI fixes
- CIK fix
- Make CE support debug only
- IP discovery fix
- Ring reset fixes
- GPUVM fault memory barrier fix
- Drop unused structures in amdgpu_drm.h
- JPEG debugfs fix
- VRAM handling fixes for GPUs without VRAM
- GC 12 MES fixes
amdkfd:
- MES fix
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://lore.kernel.org/r/20251016132224.2534946-1-alexander.deucher@amd.com
In dw_hdmi_rk3228_setup_hpd(), the SCLIN mask incorrectly references
the RK3328 variant. This change updates it to the RK3228-specific mask
RK3228_HDMI_SCLIN_MSK using FIELD_PREP_WM16, ensuring proper HPD and
I2C pin configuration for RK3228.
Change: RK3328_HDMI_SCLIN_MSK -> RK3228_HDMI_SCLIN_MSK
Fixes: 63df37f3fc ("drm/rockchip: dw_hdmi: switch to FIELD_PREP_WM16* macros")
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20251010173143.72733-1-alok.a.tiwari@oracle.com
When adding dependencies with drm_sched_job_add_dependency(), that
function consumes the fence reference both on success and failure, so in
the latter case the dma_fence_put() on the error path (xarray failed to
expand) is a double free.
Interestingly this bug appears to have been present ever since
commit ebd5f74255 ("drm/sched: Add dependency tracking"), since the code
back then looked like this:
drm_sched_job_add_implicit_dependencies():
...
for (i = 0; i < fence_count; i++) {
ret = drm_sched_job_add_dependency(job, fences[i]);
if (ret)
break;
}
for (; i < fence_count; i++)
dma_fence_put(fences[i]);
Which means for the failing 'i' the dma_fence_put was already a double
free. Possibly there were no users at that time, or the test cases were
insufficient to hit it.
The bug was then only noticed and fixed after
commit 9c2ba26535 ("drm/scheduler: use new iterator in drm_sched_job_add_implicit_dependencies v2")
landed, with its fixup of
commit 4eaf02d607 ("drm/scheduler: fix drm_sched_job_add_implicit_dependencies").
At that point it was a slightly different flavour of a double free, which
commit 963d0b3569 ("drm/scheduler: fix drm_sched_job_add_implicit_dependencies harder")
noticed and attempted to fix.
But it only moved the double free from happening inside the
drm_sched_job_add_dependency(), when releasing the reference not yet
obtained, to the caller, when releasing the reference already released by
the former in the failure case.
As such it is not easy to identify the right target for the fixes tag so
lets keep it simple and just continue the chain.
While fixing we also improve the comment and explain the reason for taking
the reference and not dropping it.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Fixes: 963d0b3569 ("drm/scheduler: fix drm_sched_job_add_implicit_dependencies harder")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/dri-devel/aNFbXq8OeYl3QSdm@stanley.mountain/
Cc: Christian König <christian.koenig@amd.com>
Cc: Rob Clark <robdclark@chromium.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Philipp Stanner <phasta@kernel.org>
Cc: Christian König <ckoenig.leichtzumerken@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Cc: stable@vger.kernel.org # v5.16+
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://lore.kernel.org/r/20251015084015.6273-1-tvrtko.ursulin@igalia.com
Kunit's generate_params() was recently updated to take an additional
test context parameter. Xe's IP and platform parameter generators were
updated accordingly at the same time, but the new parameter was not
added to the functions' kerneldoc, resulting in the following warnings:
Warning: drivers/gpu/drm/xe/tests/xe_pci.c:78 function parameter 'test' not described in 'xe_pci_fake_data_gen_params'
Warning: drivers/gpu/drm/xe/tests/xe_pci.c:254 function parameter 'test' not described in 'xe_pci_graphics_ip_gen_param'
Warning: drivers/gpu/drm/xe/tests/xe_pci.c:278 function parameter 'test' not described in 'xe_pci_media_ip_gen_param'
Warning: drivers/gpu/drm/xe/tests/xe_pci.c:302 function parameter 'test' not described in 'xe_pci_id_gen_param'
Warning: drivers/gpu/drm/xe/tests/xe_pci.c:390 function parameter 'test' not described in 'xe_pci_live_device_gen_param'
5 warnings as errors
Document the new parameter to eliminate the warnings and make CI happy.
Fixes: b9a214b5f6 ("kunit: Pass parameterized test context to generate_params()")
Reviewed-by: Shuicheng Lin <shuicheng.lin@intel.com>
Link: https://lore.kernel.org/r/20251013153014.2362879-2-matthew.d.roper@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
(cherry picked from commit 89e347f8a7)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
If the location madvise() is set to
DRM_XE_PREFERRED_LOC_DEFAULT_SYSTEM, the drm_pagemap in the
SVM gpu fault handler will be set to NULL. However there is nothing
that explicitly migrates the data to system if it is already present
in device memory.
In that case, set the device memory owner to NULL to ensure
data gets properly migrated to system on page-fault.
v2:
- Remove redundant dpagemap assignment (Himal Prasad Ghimiray)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com> #v1
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Link: https://lore.kernel.org/r/20251010104149.72783-2-thomas.hellstrom@linux.intel.com
Fixes: 10aa5c8060 ("drm/gpusvm, drm/xe: Fix userptr to not allow device private pages")
(cherry picked from commit 2cfcea7a74)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
In normal operation, a registered exec queue is disabled and
deregistered through the GuC, and freed only after the GuC confirms
completion. However, if the driver is forced to unbind while the exec
queue is still running, the user may call exec_destroy() after the GuC
has already been stopped and CT communication disabled.
In this case, the driver cannot receive a response from the GuC,
preventing proper cleanup of exec queue resources. Fix this by directly
releasing the resources when GuC is not running.
Here is the failure dmesg log:
"
[ 468.089581] ---[ end trace 0000000000000000 ]---
[ 468.089608] pci 0000:03:00.0: [drm] *ERROR* GT0: GUC ID manager unclean (1/65535)
[ 468.090558] pci 0000:03:00.0: [drm] GT0: total 65535
[ 468.090562] pci 0000:03:00.0: [drm] GT0: used 1
[ 468.090564] pci 0000:03:00.0: [drm] GT0: range 1..1 (1)
[ 468.092716] ------------[ cut here ]------------
[ 468.092719] WARNING: CPU: 14 PID: 4775 at drivers/gpu/drm/xe/xe_ttm_vram_mgr.c:298 ttm_vram_mgr_fini+0xf8/0x130 [xe]
"
v2: use xe_uc_fw_is_running() instead of xe_guc_ct_enabled().
As CT may go down and come back during VF migration.
Fixes: dd08ebf6c3 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Cc: stable@vger.kernel.org
Cc: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20251010172529.2967639-2-shuicheng.lin@intel.com
(cherry picked from commit 9b42321a02)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Moving to VRAM will fail if mixed mappings are present or if the page is
already located in VRAM. Atomic faults that require a move to VRAM
currently retry without attempting to evict mixed mappings or locate
existing VRAM mappings.
This patch fixes the issue by attempting to evict mixed mappings or find
existing VRAM pages when a move to VRAM fails during atomic fault
handling.
Fixes: a9ac0fa455 ("drm/xe: Strict migration policy for atomic SVM faults")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Link: https://lore.kernel.org/r/20251009130629.3531962-1-matthew.brost@intel.com
(cherry picked from commit 75188605c5)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
There may be cases in which the BAR0 also needs to move to accommodate
the bigger BAR2. However if it's not released, the BAR2 resize fails.
During the vram probe it can't be released as it's already in use by
xe_mmio for early register access.
Add a new function in xe_vram and let xe_pci call it directly before
even early device probe. This allows the BAR2 to resize in cases BAR0
also needs to move, assuming there aren't other reasons to hold that
move:
[] xe 0000:03:00.0: vgaarb: deactivate vga console
[] xe 0000:03:00.0: [drm] Attempting to resize bar from 8192MiB -> 16384MiB
[] xe 0000:03:00.0: BAR 0 [mem 0x83000000-0x83ffffff 64bit]: releasing
[] xe 0000:03:00.0: BAR 2 [mem 0x4000000000-0x41ffffffff 64bit pref]: releasing
[] pcieport 0000:02:01.0: bridge window [mem 0x4000000000-0x41ffffffff 64bit pref]: releasing
[] pcieport 0000:01:00.0: bridge window [mem 0x4000000000-0x41ffffffff 64bit pref]: releasing
[] pcieport 0000:01:00.0: bridge window [mem 0x4000000000-0x43ffffffff 64bit pref]: assigned
[] pcieport 0000:02:01.0: bridge window [mem 0x4000000000-0x43ffffffff 64bit pref]: assigned
[] xe 0000:03:00.0: BAR 2 [mem 0x4000000000-0x43ffffffff 64bit pref]: assigned
[] xe 0000:03:00.0: BAR 0 [mem 0x83000000-0x83ffffff 64bit]: assigned
[] pcieport 0000:00:01.0: PCI bridge to [bus 01-04]
[] pcieport 0000:00:01.0: bridge window [mem 0x83000000-0x840fffff]
[] pcieport 0000:00:01.0: bridge window [mem 0x4000000000-0x44007fffff 64bit pref]
[] pcieport 0000:01:00.0: PCI bridge to [bus 02-04]
[] pcieport 0000:01:00.0: bridge window [mem 0x83000000-0x840fffff]
[] pcieport 0000:01:00.0: bridge window [mem 0x4000000000-0x43ffffffff 64bit pref]
[] pcieport 0000:02:01.0: PCI bridge to [bus 03]
[] pcieport 0000:02:01.0: bridge window [mem 0x83000000-0x83ffffff]
[] pcieport 0000:02:01.0: bridge window [mem 0x4000000000-0x43ffffffff 64bit pref]
[] xe 0000:03:00.0: [drm] BAR2 resized to 16384M
[] xe 0000:03:00.0: [drm:xe_pci_probe [xe]] BATTLEMAGE e221:0000 dgfx:1 gfx:Xe2_HPG (20.02) ...
For BMG there are additional fix needed in the PCI side, but this
helps getting it to a working resize.
All the rebar logic is more pci-specific than xe-specific and can be
done very early in the probe sequence. In future it would be good to
move it out of xe_vram.c, but this refactor is left for later.
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: stable@vger.kernel.org # 6.12+
Link: https://lore.kernel.org/intel-xe/fafda2a3-fc63-ce97-d22b-803f771a4d19@linux.intel.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20250918-xe-pci-rebar-2-v1-2-6c094702a074@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
(cherry picked from commit 45e33f220f)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
By design the MES will return an array result that is twice the number
of hung doorbells it can report.
i.e. if up k reported doorbells are supported, then the
second half of the array, also of length k, holds the HQD information
(type/queue/pipe) where queue 1 corresponds to index 0 and k,
queue 2 corresponds to index 1 and k + 1 etc ...
The driver will use the HDQ info to target queue/pipe reset for
hardware scheduled user compute queues.
Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Initialized doorbells should be set to invalid rather than 0 to prevent
driver from over counting hung doorbells since it checks against the
invalid value to begin with.
Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
GFX12 MES uses low 32 bits of status return for success (1 or 0)
and high bits for debug information if low bits are 0.
GFX11 MES doesn't do this so checking full 64-bit status return
for 1 or 0 is still valid.
Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Previously, APU platforms (and other scenarios with uninitialized VRAM managers)
triggered a NULL pointer dereference in `ttm_resource_manager_usage()`. The root
cause is not that the `struct ttm_resource_manager *man` pointer itself is NULL,
but that `man->bdev` (the backing device pointer within the manager) remains
uninitialized (NULL) on APUs—since APUs lack dedicated VRAM and do not fully
set up VRAM manager structures. When `ttm_resource_manager_usage()` attempts to
acquire `man->bdev->lru_lock`, it dereferences the NULL `man->bdev`, leading to
a kernel OOPS.
1. **amdgpu_cs.c**: Extend the existing bandwidth control check in
`amdgpu_cs_get_threshold_for_moves()` to include a check for
`ttm_resource_manager_used()`. If the manager is not used (uninitialized
`bdev`), return 0 for migration thresholds immediately—skipping VRAM-specific
logic that would trigger the NULL dereference.
2. **amdgpu_kms.c**: Update the `AMDGPU_INFO_VRAM_USAGE` ioctl and memory info
reporting to use a conditional: if the manager is used, return the real VRAM
usage; otherwise, return 0. This avoids accessing `man->bdev` when it is
NULL.
3. **amdgpu_virt.c**: Modify the vf2pf (virtual function to physical function)
data write path. Use `ttm_resource_manager_used()` to check validity: if the
manager is usable, calculate `fb_usage` from VRAM usage; otherwise, set
`fb_usage` to 0 (APUs have no discrete framebuffer to report).
This approach is more robust than APU-specific checks because it:
- Works for all scenarios where the VRAM manager is uninitialized (not just APUs),
- Aligns with TTM's design by using its native helper function,
- Preserves correct behavior for discrete GPUs (which have fully initialized
`man->bdev` and pass the `ttm_resource_manager_used()` check).
v4: use ttm_resource_manager_used(&adev->mman.vram_mgr.manager) instead of checking the adev->gmc.is_app_apu flag (Christian)
Reviewed-by: Christian König <christian.koenig@amd.com>
Suggested-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Jesse Zhang <Jesse.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Remove extra multiplication.
CIK GPUs such as Hawaii appear to use PP_TABLE_V0 in which case
the shutdown temperature is hardcoded in smu7_init_dpm_defaults
and is already multiplied by 1000. The value was mistakenly
multiplied another time by smu7_get_thermal_temperature_range.
Fixes: 4ba082572a ("drm/amd/powerplay: export the thermal ranges of VI asics (V2)")
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/1676
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
The atomic variable vm_fault_info_updated is used to synchronize access to
adev->gmc.vm_fault_info between the interrupt handler and
get_vm_fault_info().
The default atomic functions like atomic_set() and atomic_read() do not
provide memory barriers. This allows for CPU instruction reordering,
meaning the memory accesses to vm_fault_info and the vm_fault_info_updated
flag are not guaranteed to occur in the intended order. This creates a
race condition that can lead to inconsistent or stale data being used.
The previous implementation, which used an explicit mb(), was incomplete
and inefficient. It failed to account for all potential CPU reorderings,
such as the access of vm_fault_info being reordered before the atomic_read
of the flag. This approach is also more verbose and less performant than
using the proper atomic functions with acquire/release semantics.
Fix this by switching to atomic_set_release() and atomic_read_acquire().
These functions provide the necessary acquire and release semantics,
which act as memory barriers to ensure the correct order of operations.
It is also more efficient and idiomatic than using explicit full memory
barriers.
Fixes: b97dfa27ef ("drm/amdgpu: save vm fault information for amdkfd")
Cc: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han <hanguidong02@gmail.com>
Signed-off-by: Felix Kuehling <felix.kuehling@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
When we backup ring contents to reemit after a queue reset,
we don't backup ring contents from the bad context. When
we signal the fences, we should set an error on those
fences as well.
v2: misc cleanups
v3: add locking for fence error, fix comment (Christian)
v4: fix wrap around, locking (Christian)
Fixes: 77cc0da39c ("drm/amdgpu: track ring state associated with a fence")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
