<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/gpu/drm, branch v5.4.296</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>drm/exynos: exynos7_drm_decon: add vblank check in IRQ handling</title>
<updated>2025-07-17T16:25:01+00:00</updated>
<author>
<name>Kaustabh Chakraborty</name>
<email>kauschluss@disroot.org</email>
</author>
<published>2025-06-26T19:20:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b4e72c0bf878f02faa00a7dc7c9ffc4ff7c116a7'/>
<id>b4e72c0bf878f02faa00a7dc7c9ffc4ff7c116a7</id>
<content type='text'>
commit b846350aa272de99bf6fecfa6b08e64ebfb13173 upstream.

If there's support for another console device (such as a TTY serial),
the kernel occasionally panics during boot. The panic message and a
relevant snippet of the call stack is as follows:

  Unable to handle kernel NULL pointer dereference at virtual address 000000000000000
  Call trace:
    drm_crtc_handle_vblank+0x10/0x30 (P)
    decon_irq_handler+0x88/0xb4
    [...]

Otherwise, the panics don't happen. This indicates that it's some sort
of race condition.

Add a check to validate if the drm device can handle vblanks before
calling drm_crtc_handle_vblank() to avoid this.

Cc: stable@vger.kernel.org
Fixes: 96976c3d9aff ("drm/exynos: Add DECON driver")
Signed-off-by: Kaustabh Chakraborty &lt;kauschluss@disroot.org&gt;
Signed-off-by: Inki Dae &lt;inki.dae@samsung.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b846350aa272de99bf6fecfa6b08e64ebfb13173 upstream.

If there's support for another console device (such as a TTY serial),
the kernel occasionally panics during boot. The panic message and a
relevant snippet of the call stack is as follows:

  Unable to handle kernel NULL pointer dereference at virtual address 000000000000000
  Call trace:
    drm_crtc_handle_vblank+0x10/0x30 (P)
    decon_irq_handler+0x88/0xb4
    [...]

Otherwise, the panics don't happen. This indicates that it's some sort
of race condition.

Add a check to validate if the drm device can handle vblanks before
calling drm_crtc_handle_vblank() to avoid this.

Cc: stable@vger.kernel.org
Fixes: 96976c3d9aff ("drm/exynos: Add DECON driver")
Signed-off-by: Kaustabh Chakraborty &lt;kauschluss@disroot.org&gt;
Signed-off-by: Inki Dae &lt;inki.dae@samsung.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/i915/gt: Fix timeline left held on VMA alloc error</title>
<updated>2025-07-17T16:25:00+00:00</updated>
<author>
<name>Janusz Krzysztofik</name>
<email>janusz.krzysztofik@linux.intel.com</email>
</author>
<published>2025-07-07T20:34:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=60b757730884e4a223152a68d9b5f625dac94119'/>
<id>60b757730884e4a223152a68d9b5f625dac94119</id>
<content type='text'>
[ Upstream commit a5aa7bc1fca78c7fa127d9e33aa94a0c9066c1d6 ]

The following error has been reported sporadically by CI when a test
unbinds the i915 driver on a ring submission platform:

&lt;4&gt; [239.330153] ------------[ cut here ]------------
&lt;4&gt; [239.330166] i915 0000:00:02.0: [drm] drm_WARN_ON(dev_priv-&gt;mm.shrink_count)
&lt;4&gt; [239.330196] WARNING: CPU: 1 PID: 18570 at drivers/gpu/drm/i915/i915_gem.c:1309 i915_gem_cleanup_early+0x13e/0x150 [i915]
...
&lt;4&gt; [239.330640] RIP: 0010:i915_gem_cleanup_early+0x13e/0x150 [i915]
...
&lt;4&gt; [239.330942] Call Trace:
&lt;4&gt; [239.330944]  &lt;TASK&gt;
&lt;4&gt; [239.330949]  i915_driver_late_release+0x2b/0xa0 [i915]
&lt;4&gt; [239.331202]  i915_driver_release+0x86/0xa0 [i915]
&lt;4&gt; [239.331482]  devm_drm_dev_init_release+0x61/0x90
&lt;4&gt; [239.331494]  devm_action_release+0x15/0x30
&lt;4&gt; [239.331504]  release_nodes+0x3d/0x120
&lt;4&gt; [239.331517]  devres_release_all+0x96/0xd0
&lt;4&gt; [239.331533]  device_unbind_cleanup+0x12/0x80
&lt;4&gt; [239.331543]  device_release_driver_internal+0x23a/0x280
&lt;4&gt; [239.331550]  ? bus_find_device+0xa5/0xe0
&lt;4&gt; [239.331563]  device_driver_detach+0x14/0x20
...
&lt;4&gt; [357.719679] ---[ end trace 0000000000000000 ]---

If the test also unloads the i915 module then that's followed with:

&lt;3&gt; [357.787478] =============================================================================
&lt;3&gt; [357.788006] BUG i915_vma (Tainted: G     U  W        N ): Objects remaining on __kmem_cache_shutdown()
&lt;3&gt; [357.788031] -----------------------------------------------------------------------------
&lt;3&gt; [357.788204] Object 0xffff888109e7f480 @offset=29824
&lt;3&gt; [357.788670] Allocated in i915_vma_instance+0xee/0xc10 [i915] age=292729 cpu=4 pid=2244
&lt;4&gt; [357.788994]  i915_vma_instance+0xee/0xc10 [i915]
&lt;4&gt; [357.789290]  init_status_page+0x7b/0x420 [i915]
&lt;4&gt; [357.789532]  intel_engines_init+0x1d8/0x980 [i915]
&lt;4&gt; [357.789772]  intel_gt_init+0x175/0x450 [i915]
&lt;4&gt; [357.790014]  i915_gem_init+0x113/0x340 [i915]
&lt;4&gt; [357.790281]  i915_driver_probe+0x847/0xed0 [i915]
&lt;4&gt; [357.790504]  i915_pci_probe+0xe6/0x220 [i915]
...

Closer analysis of CI results history has revealed a dependency of the
error on a few IGT tests, namely:
- igt@api_intel_allocator@fork-simple-stress-signal,
- igt@api_intel_allocator@two-level-inception-interruptible,
- igt@gem_linear_blits@interruptible,
- igt@prime_mmap_coherency@ioctl-errors,
which invisibly trigger the issue, then exhibited with first driver unbind
attempt.

All of the above tests perform actions which are actively interrupted with
signals.  Further debugging has allowed to narrow that scope down to
DRM_IOCTL_I915_GEM_EXECBUFFER2, and ring_context_alloc(), specific to ring
submission, in particular.

If successful then that function, or its execlists or GuC submission
equivalent, is supposed to be called only once per GEM context engine,
followed by raise of a flag that prevents the function from being called
again.  The function is expected to unwind its internal errors itself, so
it may be safely called once more after it returns an error.

In case of ring submission, the function first gets a reference to the
engine's legacy timeline and then allocates a VMA.  If the VMA allocation
fails, e.g. when i915_vma_instance() called from inside is interrupted
with a signal, then ring_context_alloc() fails, leaving the timeline held
referenced.  On next I915_GEM_EXECBUFFER2 IOCTL, another reference to the
timeline is got, and only that last one is put on successful completion.
As a consequence, the legacy timeline, with its underlying engine status
page's VMA object, is still held and not released on driver unbind.

Get the legacy timeline only after successful allocation of the context
engine's VMA.

v2: Add a note on other submission methods (Krzysztof Karas):
    Both execlists and GuC submission use lrc_alloc() which seems free
    from a similar issue.

Fixes: 75d0a7f31eec ("drm/i915: Lift timeline into intel_context")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12061
Cc: Chris Wilson &lt;chris.p.wilson@linux.intel.com&gt;
Cc: Matthew Auld &lt;matthew.auld@intel.com&gt;
Cc: Krzysztof Karas &lt;krzysztof.karas@intel.com&gt;
Reviewed-by: Sebastian Brzezinka &lt;sebastian.brzezinka@intel.com&gt;
Reviewed-by: Krzysztof Niemiec &lt;krzysztof.niemiec@intel.com&gt;
Signed-off-by: Janusz Krzysztofik &lt;janusz.krzysztofik@linux.intel.com&gt;
Reviewed-by: Nitin Gote &lt;nitin.r.gote@intel.com&gt;
Reviewed-by: Andi Shyti &lt;andi.shyti@linux.intel.com&gt;
Signed-off-by: Andi Shyti &lt;andi.shyti@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20250611104352.1014011-2-janusz.krzysztofik@linux.intel.com
(cherry picked from commit cc43422b3cc79eacff4c5a8ba0d224688ca9dd4f)
Signed-off-by: Joonas Lahtinen &lt;joonas.lahtinen@linux.intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit a5aa7bc1fca78c7fa127d9e33aa94a0c9066c1d6 ]

The following error has been reported sporadically by CI when a test
unbinds the i915 driver on a ring submission platform:

&lt;4&gt; [239.330153] ------------[ cut here ]------------
&lt;4&gt; [239.330166] i915 0000:00:02.0: [drm] drm_WARN_ON(dev_priv-&gt;mm.shrink_count)
&lt;4&gt; [239.330196] WARNING: CPU: 1 PID: 18570 at drivers/gpu/drm/i915/i915_gem.c:1309 i915_gem_cleanup_early+0x13e/0x150 [i915]
...
&lt;4&gt; [239.330640] RIP: 0010:i915_gem_cleanup_early+0x13e/0x150 [i915]
...
&lt;4&gt; [239.330942] Call Trace:
&lt;4&gt; [239.330944]  &lt;TASK&gt;
&lt;4&gt; [239.330949]  i915_driver_late_release+0x2b/0xa0 [i915]
&lt;4&gt; [239.331202]  i915_driver_release+0x86/0xa0 [i915]
&lt;4&gt; [239.331482]  devm_drm_dev_init_release+0x61/0x90
&lt;4&gt; [239.331494]  devm_action_release+0x15/0x30
&lt;4&gt; [239.331504]  release_nodes+0x3d/0x120
&lt;4&gt; [239.331517]  devres_release_all+0x96/0xd0
&lt;4&gt; [239.331533]  device_unbind_cleanup+0x12/0x80
&lt;4&gt; [239.331543]  device_release_driver_internal+0x23a/0x280
&lt;4&gt; [239.331550]  ? bus_find_device+0xa5/0xe0
&lt;4&gt; [239.331563]  device_driver_detach+0x14/0x20
...
&lt;4&gt; [357.719679] ---[ end trace 0000000000000000 ]---

If the test also unloads the i915 module then that's followed with:

&lt;3&gt; [357.787478] =============================================================================
&lt;3&gt; [357.788006] BUG i915_vma (Tainted: G     U  W        N ): Objects remaining on __kmem_cache_shutdown()
&lt;3&gt; [357.788031] -----------------------------------------------------------------------------
&lt;3&gt; [357.788204] Object 0xffff888109e7f480 @offset=29824
&lt;3&gt; [357.788670] Allocated in i915_vma_instance+0xee/0xc10 [i915] age=292729 cpu=4 pid=2244
&lt;4&gt; [357.788994]  i915_vma_instance+0xee/0xc10 [i915]
&lt;4&gt; [357.789290]  init_status_page+0x7b/0x420 [i915]
&lt;4&gt; [357.789532]  intel_engines_init+0x1d8/0x980 [i915]
&lt;4&gt; [357.789772]  intel_gt_init+0x175/0x450 [i915]
&lt;4&gt; [357.790014]  i915_gem_init+0x113/0x340 [i915]
&lt;4&gt; [357.790281]  i915_driver_probe+0x847/0xed0 [i915]
&lt;4&gt; [357.790504]  i915_pci_probe+0xe6/0x220 [i915]
...

Closer analysis of CI results history has revealed a dependency of the
error on a few IGT tests, namely:
- igt@api_intel_allocator@fork-simple-stress-signal,
- igt@api_intel_allocator@two-level-inception-interruptible,
- igt@gem_linear_blits@interruptible,
- igt@prime_mmap_coherency@ioctl-errors,
which invisibly trigger the issue, then exhibited with first driver unbind
attempt.

All of the above tests perform actions which are actively interrupted with
signals.  Further debugging has allowed to narrow that scope down to
DRM_IOCTL_I915_GEM_EXECBUFFER2, and ring_context_alloc(), specific to ring
submission, in particular.

If successful then that function, or its execlists or GuC submission
equivalent, is supposed to be called only once per GEM context engine,
followed by raise of a flag that prevents the function from being called
again.  The function is expected to unwind its internal errors itself, so
it may be safely called once more after it returns an error.

In case of ring submission, the function first gets a reference to the
engine's legacy timeline and then allocates a VMA.  If the VMA allocation
fails, e.g. when i915_vma_instance() called from inside is interrupted
with a signal, then ring_context_alloc() fails, leaving the timeline held
referenced.  On next I915_GEM_EXECBUFFER2 IOCTL, another reference to the
timeline is got, and only that last one is put on successful completion.
As a consequence, the legacy timeline, with its underlying engine status
page's VMA object, is still held and not released on driver unbind.

Get the legacy timeline only after successful allocation of the context
engine's VMA.

v2: Add a note on other submission methods (Krzysztof Karas):
    Both execlists and GuC submission use lrc_alloc() which seems free
    from a similar issue.

Fixes: 75d0a7f31eec ("drm/i915: Lift timeline into intel_context")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12061
Cc: Chris Wilson &lt;chris.p.wilson@linux.intel.com&gt;
Cc: Matthew Auld &lt;matthew.auld@intel.com&gt;
Cc: Krzysztof Karas &lt;krzysztof.karas@intel.com&gt;
Reviewed-by: Sebastian Brzezinka &lt;sebastian.brzezinka@intel.com&gt;
Reviewed-by: Krzysztof Niemiec &lt;krzysztof.niemiec@intel.com&gt;
Signed-off-by: Janusz Krzysztofik &lt;janusz.krzysztofik@linux.intel.com&gt;
Reviewed-by: Nitin Gote &lt;nitin.r.gote@intel.com&gt;
Reviewed-by: Andi Shyti &lt;andi.shyti@linux.intel.com&gt;
Signed-off-by: Andi Shyti &lt;andi.shyti@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20250611104352.1014011-2-janusz.krzysztofik@linux.intel.com
(cherry picked from commit cc43422b3cc79eacff4c5a8ba0d224688ca9dd4f)
Signed-off-by: Joonas Lahtinen &lt;joonas.lahtinen@linux.intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/i915/selftests: Change mock_request() to return error pointers</title>
<updated>2025-07-17T16:25:00+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@linaro.org</email>
</author>
<published>2025-06-25T15:21:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6d2d741052a4740d12c7d0c4040f3d6a500b5f97'/>
<id>6d2d741052a4740d12c7d0c4040f3d6a500b5f97</id>
<content type='text'>
[ Upstream commit caa7c7a76b78ce41d347003f84975125383e6b59 ]

There was an error pointer vs NULL bug in __igt_breadcrumbs_smoketest().
The __mock_request_alloc() function implements the
smoketest-&gt;request_alloc() function pointer.  It was supposed to return
error pointers, but it propogates the NULL return from mock_request()
so in the event of a failure, it would lead to a NULL pointer
dereference.

To fix this, change the mock_request() function to return error pointers
and update all the callers to expect that.

Fixes: 52c0fdb25c7c ("drm/i915: Replace global breadcrumbs with per-context interrupt tracking")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Reviewed-by: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
Link: https://lore.kernel.org/r/685c1417.050a0220.696f5.5c05@mx.google.com
Signed-off-by: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
(cherry picked from commit 778fa8ad5f0f23397d045c7ebca048ce8def1c43)
Signed-off-by: Joonas Lahtinen &lt;joonas.lahtinen@linux.intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit caa7c7a76b78ce41d347003f84975125383e6b59 ]

There was an error pointer vs NULL bug in __igt_breadcrumbs_smoketest().
The __mock_request_alloc() function implements the
smoketest-&gt;request_alloc() function pointer.  It was supposed to return
error pointers, but it propogates the NULL return from mock_request()
so in the event of a failure, it would lead to a NULL pointer
dereference.

To fix this, change the mock_request() function to return error pointers
and update all the callers to expect that.

Fixes: 52c0fdb25c7c ("drm/i915: Replace global breadcrumbs with per-context interrupt tracking")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Reviewed-by: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
Link: https://lore.kernel.org/r/685c1417.050a0220.696f5.5c05@mx.google.com
Signed-off-by: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
(cherry picked from commit 778fa8ad5f0f23397d045c7ebca048ce8def1c43)
Signed-off-by: Joonas Lahtinen &lt;joonas.lahtinen@linux.intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/v3d: Disable interrupts before resetting the GPU</title>
<updated>2025-07-17T16:24:58+00:00</updated>
<author>
<name>Maíra Canal</name>
<email>mcanal@igalia.com</email>
</author>
<published>2025-06-28T22:42:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b9c403d1236cecb10dd0246a30d81e4b265f8e8d'/>
<id>b9c403d1236cecb10dd0246a30d81e4b265f8e8d</id>
<content type='text'>
[ Upstream commit 226862f50a7a88e4e4de9abbf36c64d19acd6fd0 ]

Currently, an interrupt can be triggered during a GPU reset, which can
lead to GPU hangs and NULL pointer dereference in an interrupt context
as shown in the following trace:

 [  314.035040] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000c0
 [  314.043822] Mem abort info:
 [  314.046606]   ESR = 0x0000000096000005
 [  314.050347]   EC = 0x25: DABT (current EL), IL = 32 bits
 [  314.055651]   SET = 0, FnV = 0
 [  314.058695]   EA = 0, S1PTW = 0
 [  314.061826]   FSC = 0x05: level 1 translation fault
 [  314.066694] Data abort info:
 [  314.069564]   ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
 [  314.075039]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
 [  314.080080]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
 [  314.085382] user pgtable: 4k pages, 39-bit VAs, pgdp=0000000102728000
 [  314.091814] [00000000000000c0] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
 [  314.100511] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
 [  314.106770] Modules linked in: v3d i2c_brcmstb vc4 snd_soc_hdmi_codec gpu_sched drm_shmem_helper drm_display_helper cec drm_dma_helper drm_kms_helper drm drm_panel_orientation_quirks snd_soc_core snd_compress snd_pcm_dmaengine snd_pcm snd_timer snd backlight
 [  314.129654] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.25+rpt-rpi-v8 #1  Debian 1:6.12.25-1+rpt1
 [  314.139388] Hardware name: Raspberry Pi 4 Model B Rev 1.4 (DT)
 [  314.145211] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 [  314.152165] pc : v3d_irq+0xec/0x2e0 [v3d]
 [  314.156187] lr : v3d_irq+0xe0/0x2e0 [v3d]
 [  314.160198] sp : ffffffc080003ea0
 [  314.163502] x29: ffffffc080003ea0 x28: ffffffec1f184980 x27: 021202b000000000
 [  314.170633] x26: ffffffec1f17f630 x25: ffffff8101372000 x24: ffffffec1f17d9f0
 [  314.177764] x23: 000000000000002a x22: 000000000000002a x21: ffffff8103252000
 [  314.184895] x20: 0000000000000001 x19: 00000000deadbeef x18: 0000000000000000
 [  314.192026] x17: ffffff94e51d2000 x16: ffffffec1dac3cb0 x15: c306000000000000
 [  314.199156] x14: 0000000000000000 x13: b2fc982e03cc5168 x12: 0000000000000001
 [  314.206286] x11: ffffff8103f8bcc0 x10: ffffffec1f196868 x9 : ffffffec1dac3874
 [  314.213416] x8 : 0000000000000000 x7 : 0000000000042a3a x6 : ffffff810017a180
 [  314.220547] x5 : ffffffec1ebad400 x4 : ffffffec1ebad320 x3 : 00000000000bebeb
 [  314.227677] x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000
 [  314.234807] Call trace:
 [  314.237243]  v3d_irq+0xec/0x2e0 [v3d]
 [  314.240906]  __handle_irq_event_percpu+0x58/0x218
 [  314.245609]  handle_irq_event+0x54/0xb8
 [  314.249439]  handle_fasteoi_irq+0xac/0x240
 [  314.253527]  handle_irq_desc+0x48/0x68
 [  314.257269]  generic_handle_domain_irq+0x24/0x38
 [  314.261879]  gic_handle_irq+0x48/0xd8
 [  314.265533]  call_on_irq_stack+0x24/0x58
 [  314.269448]  do_interrupt_handler+0x88/0x98
 [  314.273624]  el1_interrupt+0x34/0x68
 [  314.277193]  el1h_64_irq_handler+0x18/0x28
 [  314.281281]  el1h_64_irq+0x64/0x68
 [  314.284673]  default_idle_call+0x3c/0x168
 [  314.288675]  do_idle+0x1fc/0x230
 [  314.291895]  cpu_startup_entry+0x3c/0x50
 [  314.295810]  rest_init+0xe4/0xf0
 [  314.299030]  start_kernel+0x5e8/0x790
 [  314.302684]  __primary_switched+0x80/0x90
 [  314.306691] Code: 940029eb 360ffc13 f9442ea0 52800001 (f9406017)
 [  314.312775] ---[ end trace 0000000000000000 ]---
 [  314.317384] Kernel panic - not syncing: Oops: Fatal exception in interrupt
 [  314.324249] SMP: stopping secondary CPUs
 [  314.328167] Kernel Offset: 0x2b9da00000 from 0xffffffc080000000
 [  314.334076] PHYS_OFFSET: 0x0
 [  314.336946] CPU features: 0x08,00002013,c0200000,0200421b
 [  314.342337] Memory Limit: none
 [  314.345382] ---[ end Kernel panic - not syncing: Oops: Fatal exception in interrupt ]---

Before resetting the GPU, it's necessary to disable all interrupts and
deal with any interrupt handler still in-flight. Otherwise, the GPU might
reset with jobs still running, or yet, an interrupt could be handled
during the reset.

Cc: stable@vger.kernel.org
Fixes: 57692c94dcbe ("drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+")
Reviewed-by: Juan A. Suarez &lt;jasuarez@igalia.com&gt;
Reviewed-by: Iago Toral Quiroga &lt;itoral@igalia.com&gt;
Link: https://lore.kernel.org/r/20250628224243.47599-1-mcanal@igalia.com
Signed-off-by: Maíra Canal &lt;mcanal@igalia.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 226862f50a7a88e4e4de9abbf36c64d19acd6fd0 ]

Currently, an interrupt can be triggered during a GPU reset, which can
lead to GPU hangs and NULL pointer dereference in an interrupt context
as shown in the following trace:

 [  314.035040] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000c0
 [  314.043822] Mem abort info:
 [  314.046606]   ESR = 0x0000000096000005
 [  314.050347]   EC = 0x25: DABT (current EL), IL = 32 bits
 [  314.055651]   SET = 0, FnV = 0
 [  314.058695]   EA = 0, S1PTW = 0
 [  314.061826]   FSC = 0x05: level 1 translation fault
 [  314.066694] Data abort info:
 [  314.069564]   ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
 [  314.075039]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
 [  314.080080]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
 [  314.085382] user pgtable: 4k pages, 39-bit VAs, pgdp=0000000102728000
 [  314.091814] [00000000000000c0] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
 [  314.100511] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
 [  314.106770] Modules linked in: v3d i2c_brcmstb vc4 snd_soc_hdmi_codec gpu_sched drm_shmem_helper drm_display_helper cec drm_dma_helper drm_kms_helper drm drm_panel_orientation_quirks snd_soc_core snd_compress snd_pcm_dmaengine snd_pcm snd_timer snd backlight
 [  314.129654] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.25+rpt-rpi-v8 #1  Debian 1:6.12.25-1+rpt1
 [  314.139388] Hardware name: Raspberry Pi 4 Model B Rev 1.4 (DT)
 [  314.145211] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 [  314.152165] pc : v3d_irq+0xec/0x2e0 [v3d]
 [  314.156187] lr : v3d_irq+0xe0/0x2e0 [v3d]
 [  314.160198] sp : ffffffc080003ea0
 [  314.163502] x29: ffffffc080003ea0 x28: ffffffec1f184980 x27: 021202b000000000
 [  314.170633] x26: ffffffec1f17f630 x25: ffffff8101372000 x24: ffffffec1f17d9f0
 [  314.177764] x23: 000000000000002a x22: 000000000000002a x21: ffffff8103252000
 [  314.184895] x20: 0000000000000001 x19: 00000000deadbeef x18: 0000000000000000
 [  314.192026] x17: ffffff94e51d2000 x16: ffffffec1dac3cb0 x15: c306000000000000
 [  314.199156] x14: 0000000000000000 x13: b2fc982e03cc5168 x12: 0000000000000001
 [  314.206286] x11: ffffff8103f8bcc0 x10: ffffffec1f196868 x9 : ffffffec1dac3874
 [  314.213416] x8 : 0000000000000000 x7 : 0000000000042a3a x6 : ffffff810017a180
 [  314.220547] x5 : ffffffec1ebad400 x4 : ffffffec1ebad320 x3 : 00000000000bebeb
 [  314.227677] x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000
 [  314.234807] Call trace:
 [  314.237243]  v3d_irq+0xec/0x2e0 [v3d]
 [  314.240906]  __handle_irq_event_percpu+0x58/0x218
 [  314.245609]  handle_irq_event+0x54/0xb8
 [  314.249439]  handle_fasteoi_irq+0xac/0x240
 [  314.253527]  handle_irq_desc+0x48/0x68
 [  314.257269]  generic_handle_domain_irq+0x24/0x38
 [  314.261879]  gic_handle_irq+0x48/0xd8
 [  314.265533]  call_on_irq_stack+0x24/0x58
 [  314.269448]  do_interrupt_handler+0x88/0x98
 [  314.273624]  el1_interrupt+0x34/0x68
 [  314.277193]  el1h_64_irq_handler+0x18/0x28
 [  314.281281]  el1h_64_irq+0x64/0x68
 [  314.284673]  default_idle_call+0x3c/0x168
 [  314.288675]  do_idle+0x1fc/0x230
 [  314.291895]  cpu_startup_entry+0x3c/0x50
 [  314.295810]  rest_init+0xe4/0xf0
 [  314.299030]  start_kernel+0x5e8/0x790
 [  314.302684]  __primary_switched+0x80/0x90
 [  314.306691] Code: 940029eb 360ffc13 f9442ea0 52800001 (f9406017)
 [  314.312775] ---[ end trace 0000000000000000 ]---
 [  314.317384] Kernel panic - not syncing: Oops: Fatal exception in interrupt
 [  314.324249] SMP: stopping secondary CPUs
 [  314.328167] Kernel Offset: 0x2b9da00000 from 0xffffffc080000000
 [  314.334076] PHYS_OFFSET: 0x0
 [  314.336946] CPU features: 0x08,00002013,c0200000,0200421b
 [  314.342337] Memory Limit: none
 [  314.345382] ---[ end Kernel panic - not syncing: Oops: Fatal exception in interrupt ]---

Before resetting the GPU, it's necessary to disable all interrupts and
deal with any interrupt handler still in-flight. Otherwise, the GPU might
reset with jobs still running, or yet, an interrupt could be handled
during the reset.

Cc: stable@vger.kernel.org
Fixes: 57692c94dcbe ("drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+")
Reviewed-by: Juan A. Suarez &lt;jasuarez@igalia.com&gt;
Reviewed-by: Iago Toral Quiroga &lt;itoral@igalia.com&gt;
Link: https://lore.kernel.org/r/20250628224243.47599-1-mcanal@igalia.com
Signed-off-by: Maíra Canal &lt;mcanal@igalia.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/exynos: fimd: Guard display clock control with runtime PM calls</title>
<updated>2025-07-17T16:24:56+00:00</updated>
<author>
<name>Marek Szyprowski</name>
<email>m.szyprowski@samsung.com</email>
</author>
<published>2025-06-18T12:06:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=71ac65ebd9bf5b9f0a84f0cb6f64896f559a1e94'/>
<id>71ac65ebd9bf5b9f0a84f0cb6f64896f559a1e94</id>
<content type='text'>
[ Upstream commit 5d91394f236167ac624b823820faf4aa928b889e ]

Commit c9b1150a68d9 ("drm/atomic-helper: Re-order bridge chain pre-enable
and post-disable") changed the call sequence to the CRTC enable/disable
and bridge pre_enable/post_disable methods, so those bridge methods are
now called when CRTC is not yet enabled.

This causes a lockup observed on Samsung Peach-Pit/Pi Chromebooks. The
source of this lockup is a call to fimd_dp_clock_enable() function, when
FIMD device is not yet runtime resumed. It worked before the mentioned
commit only because the CRTC implemented by the FIMD driver was always
enabled what guaranteed the FIMD device to be runtime resumed.

This patch adds runtime PM guards to the fimd_dp_clock_enable() function
to enable its proper operation also when the CRTC implemented by FIMD is
not yet enabled.

Fixes: 196e059a8a6a ("drm/exynos: convert clock_enable crtc callback to pipeline clock")
Signed-off-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Reviewed-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Signed-off-by: Inki Dae &lt;inki.dae@samsung.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 5d91394f236167ac624b823820faf4aa928b889e ]

Commit c9b1150a68d9 ("drm/atomic-helper: Re-order bridge chain pre-enable
and post-disable") changed the call sequence to the CRTC enable/disable
and bridge pre_enable/post_disable methods, so those bridge methods are
now called when CRTC is not yet enabled.

This causes a lockup observed on Samsung Peach-Pit/Pi Chromebooks. The
source of this lockup is a call to fimd_dp_clock_enable() function, when
FIMD device is not yet runtime resumed. It worked before the mentioned
commit only because the CRTC implemented by the FIMD driver was always
enabled what guaranteed the FIMD device to be runtime resumed.

This patch adds runtime PM guards to the fimd_dp_clock_enable() function
to enable its proper operation also when the CRTC implemented by FIMD is
not yet enabled.

Fixes: 196e059a8a6a ("drm/exynos: convert clock_enable crtc callback to pipeline clock")
Signed-off-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Reviewed-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Signed-off-by: Inki Dae &lt;inki.dae@samsung.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/bridge: cdns-dsi: Check return value when getting default PHY config</title>
<updated>2025-07-17T16:24:55+00:00</updated>
<author>
<name>Aradhya Bhatia</name>
<email>a-bhatia1@ti.com</email>
</author>
<published>2025-03-29T11:39:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c1a4677f7c9c0e5cd87b1c788ae28564110240d2'/>
<id>c1a4677f7c9c0e5cd87b1c788ae28564110240d2</id>
<content type='text'>
commit c6a7ef0d4856b9629df390e9935d7fd67fe39f81 upstream.

Check for the return value of the phy_mipi_dphy_get_default_config()
call, and in case of an error, return back the same.

Fixes: fced5a364dee ("drm/bridge: cdns: Convert to phy framework")
Cc: stable@vger.kernel.org
Reviewed-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Tested-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Signed-off-by: Aradhya Bhatia &lt;a-bhatia1@ti.com&gt;
Signed-off-by: Aradhya Bhatia &lt;aradhya.bhatia@linux.dev&gt;
Link: https://lore.kernel.org/r/20250329113925.68204-5-aradhya.bhatia@linux.dev
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c6a7ef0d4856b9629df390e9935d7fd67fe39f81 upstream.

Check for the return value of the phy_mipi_dphy_get_default_config()
call, and in case of an error, return back the same.

Fixes: fced5a364dee ("drm/bridge: cdns: Convert to phy framework")
Cc: stable@vger.kernel.org
Reviewed-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Tested-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Signed-off-by: Aradhya Bhatia &lt;a-bhatia1@ti.com&gt;
Signed-off-by: Aradhya Bhatia &lt;aradhya.bhatia@linux.dev&gt;
Link: https://lore.kernel.org/r/20250329113925.68204-5-aradhya.bhatia@linux.dev
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/bridge: cdns-dsi: Fix connecting to next bridge</title>
<updated>2025-07-17T16:24:55+00:00</updated>
<author>
<name>Aradhya Bhatia</name>
<email>a-bhatia1@ti.com</email>
</author>
<published>2025-03-29T11:39:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7aa42abc8d5764123b99cf848484d641a34aa444'/>
<id>7aa42abc8d5764123b99cf848484d641a34aa444</id>
<content type='text'>
commit 688eb4d465484bc2a3471a6a6f06f833b58c7867 upstream.

Fix the OF node pointer passed to the of_drm_find_bridge() call to find
the next bridge in the display chain.

The code to find the next panel (and create its panel-bridge) works
fine, but to find the next (non-panel) bridge does not.

To find the next bridge in the pipeline, we need to pass "np" - the OF
node pointer of the next entity in the devicetree chain. Passing
"of_node" to of_drm_find_bridge (which is what the code does currently)
will fetch the bridge for the cdns-dsi which is not what's required.

Fix that.

Fixes: e19233955d9e ("drm/bridge: Add Cadence DSI driver")
Cc: stable@vger.kernel.org
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Reviewed-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Tested-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Signed-off-by: Aradhya Bhatia &lt;a-bhatia1@ti.com&gt;
Signed-off-by: Aradhya Bhatia &lt;aradhya.bhatia@linux.dev&gt;
Link: https://lore.kernel.org/r/20250329113925.68204-2-aradhya.bhatia@linux.dev
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 688eb4d465484bc2a3471a6a6f06f833b58c7867 upstream.

Fix the OF node pointer passed to the of_drm_find_bridge() call to find
the next bridge in the display chain.

The code to find the next panel (and create its panel-bridge) works
fine, but to find the next (non-panel) bridge does not.

To find the next bridge in the pipeline, we need to pass "np" - the OF
node pointer of the next entity in the devicetree chain. Passing
"of_node" to of_drm_find_bridge (which is what the code does currently)
will fetch the bridge for the cdns-dsi which is not what's required.

Fix that.

Fixes: e19233955d9e ("drm/bridge: Add Cadence DSI driver")
Cc: stable@vger.kernel.org
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Reviewed-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Tested-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Signed-off-by: Aradhya Bhatia &lt;a-bhatia1@ti.com&gt;
Signed-off-by: Aradhya Bhatia &lt;aradhya.bhatia@linux.dev&gt;
Link: https://lore.kernel.org/r/20250329113925.68204-2-aradhya.bhatia@linux.dev
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/bridge: cdns-dsi: Fix the clock variable for mode_valid()</title>
<updated>2025-07-17T16:24:54+00:00</updated>
<author>
<name>Aradhya Bhatia</name>
<email>a-bhatia1@ti.com</email>
</author>
<published>2025-03-29T11:39:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0ad3721400a9930721eb36378aaa77c5d93d049a'/>
<id>0ad3721400a9930721eb36378aaa77c5d93d049a</id>
<content type='text'>
commit 132bdcec399be6ae947582249a134b38cf56731c upstream.

The crtc_* mode parameters do not get generated (duplicated in this
case) from the regular parameters before the mode validation phase
begins.

The rest of the code conditionally uses the crtc_* parameters only
during the bridge enable phase, but sticks to the regular parameters
for mode validation. In this singular instance, however, the driver
tries to use the crtc_clock parameter even during the mode validation,
causing the validation to fail.

Allow the D-Phy config checks to use mode-&gt;clock instead of
mode-&gt;crtc_clock during mode_valid checks, like everywhere else in the
driver.

Fixes: fced5a364dee ("drm/bridge: cdns: Convert to phy framework")
Cc: stable@vger.kernel.org
Reviewed-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Tested-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Signed-off-by: Aradhya Bhatia &lt;a-bhatia1@ti.com&gt;
Signed-off-by: Aradhya Bhatia &lt;aradhya.bhatia@linux.dev&gt;
Link: https://lore.kernel.org/r/20250329113925.68204-4-aradhya.bhatia@linux.dev
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 132bdcec399be6ae947582249a134b38cf56731c upstream.

The crtc_* mode parameters do not get generated (duplicated in this
case) from the regular parameters before the mode validation phase
begins.

The rest of the code conditionally uses the crtc_* parameters only
during the bridge enable phase, but sticks to the regular parameters
for mode validation. In this singular instance, however, the driver
tries to use the crtc_clock parameter even during the mode validation,
causing the validation to fail.

Allow the D-Phy config checks to use mode-&gt;clock instead of
mode-&gt;crtc_clock during mode_valid checks, like everywhere else in the
driver.

Fixes: fced5a364dee ("drm/bridge: cdns: Convert to phy framework")
Cc: stable@vger.kernel.org
Reviewed-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Tested-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Signed-off-by: Aradhya Bhatia &lt;a-bhatia1@ti.com&gt;
Signed-off-by: Aradhya Bhatia &lt;aradhya.bhatia@linux.dev&gt;
Link: https://lore.kernel.org/r/20250329113925.68204-4-aradhya.bhatia@linux.dev
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@oss.qualcomm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/tegra: Assign plane type before registration</title>
<updated>2025-07-17T16:24:54+00:00</updated>
<author>
<name>Thierry Reding</name>
<email>treding@nvidia.com</email>
</author>
<published>2025-04-21T16:13:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e52589c0165fd7068684636f5ff9128cc6c2a2ba'/>
<id>e52589c0165fd7068684636f5ff9128cc6c2a2ba</id>
<content type='text'>
commit 9ff4fdf4f44b69237c0afc1d3a8dac916ce66f3e upstream.

Changes to a plane's type after it has been registered aren't propagated
to userspace automatically. This could possibly be achieved by updating
the property, but since we can already determine which type this should
be before the registration, passing in the right type from the start is
a much better solution.

Suggested-by: Aaron Kling &lt;webgeek1234@gmail.com&gt;
Signed-off-by: Thierry Reding &lt;treding@nvidia.com&gt;
Cc: stable@vger.kernel.org
Fixes: 473079549f27 ("drm/tegra: dc: Add Tegra186 support")
Signed-off-by: Aaron Kling &lt;webgeek1234@gmail.com&gt;
Signed-off-by: Thierry Reding &lt;treding@nvidia.com&gt;
Link: https://lore.kernel.org/r/20250421-tegra-drm-primary-v2-1-7f740c4c2121@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 9ff4fdf4f44b69237c0afc1d3a8dac916ce66f3e upstream.

Changes to a plane's type after it has been registered aren't propagated
to userspace automatically. This could possibly be achieved by updating
the property, but since we can already determine which type this should
be before the registration, passing in the right type from the start is
a much better solution.

Suggested-by: Aaron Kling &lt;webgeek1234@gmail.com&gt;
Signed-off-by: Thierry Reding &lt;treding@nvidia.com&gt;
Cc: stable@vger.kernel.org
Fixes: 473079549f27 ("drm/tegra: dc: Add Tegra186 support")
Signed-off-by: Aaron Kling &lt;webgeek1234@gmail.com&gt;
Signed-off-by: Thierry Reding &lt;treding@nvidia.com&gt;
Link: https://lore.kernel.org/r/20250421-tegra-drm-primary-v2-1-7f740c4c2121@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/nouveau/bl: increase buffer size to avoid truncate warning</title>
<updated>2025-06-27T10:02:57+00:00</updated>
<author>
<name>Jacob Keller</name>
<email>jacob.e.keller@intel.com</email>
</author>
<published>2025-06-10T21:54:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=738066cdd08a12464f420652e26d2bb8165ae051'/>
<id>738066cdd08a12464f420652e26d2bb8165ae051</id>
<content type='text'>
[ Upstream commit 61b2b3737499f1fb361a54a16828db24a8345e85 ]

The nouveau_get_backlight_name() function generates a unique name for the
backlight interface, appending an id from 1 to 99 for all backlight devices
after the first.

GCC 15 (and likely other compilers) produce the following
-Wformat-truncation warning:

nouveau_backlight.c: In function ‘nouveau_backlight_init’:
nouveau_backlight.c:56:69: error: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 3 [-Werror=format-truncation=]
   56 |                 snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
      |                                                                     ^~
In function ‘nouveau_get_backlight_name’,
    inlined from ‘nouveau_backlight_init’ at nouveau_backlight.c:351:7:
nouveau_backlight.c:56:56: note: directive argument in the range [1, 2147483647]
   56 |                 snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
      |                                                        ^~~~~~~~~~~~~~~~
nouveau_backlight.c:56:17: note: ‘snprintf’ output between 14 and 23 bytes into a destination of size 15
   56 |                 snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The warning started appearing after commit ab244be47a8f ("drm/nouveau:
Fix a potential theorical leak in nouveau_get_backlight_name()") This fix
for the ida usage removed the explicit value check for ids larger than 99.
The compiler is unable to intuit that the ida_alloc_max() limits the
returned value range between 0 and 99.

Because the compiler can no longer infer that the number ranges from 0 to
99, it thinks that it could use as many as 11 digits (10 + the potential -
sign for negative numbers).

The warning has gone unfixed for some time, with at least one kernel test
robot report. The code breaks W=1 builds, which is especially frustrating
with the introduction of CONFIG_WERROR.

The string is stored temporarily on the stack and then copied into the
device name. Its not a big deal to use 11 more bytes of stack rounding out
to an even 24 bytes. Increase BL_NAME_SIZE to 24 to avoid the truncation
warning. This fixes the W=1 builds that include this driver.

Compile tested only.

Fixes: ab244be47a8f ("drm/nouveau: Fix a potential theorical leak in nouveau_get_backlight_name()")
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/oe-kbuild-all/202312050324.0kv4PnfZ-lkp@intel.com/
Suggested-by: Timur Tabi &lt;ttabi@nvidia.com&gt;
Signed-off-by: Jacob Keller &lt;jacob.e.keller@intel.com&gt;
Link: https://lore.kernel.org/r/20250610-jk-nouveua-drm-bl-snprintf-fix-v2-1-7fdd4b84b48e@intel.com
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 61b2b3737499f1fb361a54a16828db24a8345e85 ]

The nouveau_get_backlight_name() function generates a unique name for the
backlight interface, appending an id from 1 to 99 for all backlight devices
after the first.

GCC 15 (and likely other compilers) produce the following
-Wformat-truncation warning:

nouveau_backlight.c: In function ‘nouveau_backlight_init’:
nouveau_backlight.c:56:69: error: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 3 [-Werror=format-truncation=]
   56 |                 snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
      |                                                                     ^~
In function ‘nouveau_get_backlight_name’,
    inlined from ‘nouveau_backlight_init’ at nouveau_backlight.c:351:7:
nouveau_backlight.c:56:56: note: directive argument in the range [1, 2147483647]
   56 |                 snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
      |                                                        ^~~~~~~~~~~~~~~~
nouveau_backlight.c:56:17: note: ‘snprintf’ output between 14 and 23 bytes into a destination of size 15
   56 |                 snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The warning started appearing after commit ab244be47a8f ("drm/nouveau:
Fix a potential theorical leak in nouveau_get_backlight_name()") This fix
for the ida usage removed the explicit value check for ids larger than 99.
The compiler is unable to intuit that the ida_alloc_max() limits the
returned value range between 0 and 99.

Because the compiler can no longer infer that the number ranges from 0 to
99, it thinks that it could use as many as 11 digits (10 + the potential -
sign for negative numbers).

The warning has gone unfixed for some time, with at least one kernel test
robot report. The code breaks W=1 builds, which is especially frustrating
with the introduction of CONFIG_WERROR.

The string is stored temporarily on the stack and then copied into the
device name. Its not a big deal to use 11 more bytes of stack rounding out
to an even 24 bytes. Increase BL_NAME_SIZE to 24 to avoid the truncation
warning. This fixes the W=1 builds that include this driver.

Compile tested only.

Fixes: ab244be47a8f ("drm/nouveau: Fix a potential theorical leak in nouveau_get_backlight_name()")
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/oe-kbuild-all/202312050324.0kv4PnfZ-lkp@intel.com/
Suggested-by: Timur Tabi &lt;ttabi@nvidia.com&gt;
Signed-off-by: Jacob Keller &lt;jacob.e.keller@intel.com&gt;
Link: https://lore.kernel.org/r/20250610-jk-nouveua-drm-bl-snprintf-fix-v2-1-7fdd4b84b48e@intel.com
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
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