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| author | Mario Kleiner <mario.kleiner.de@gmail.com> | 2016-03-01 21:31:16 +0100 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2016-03-05 12:31:45 -0500 |
| commit | 90e94b160c7f647ddffda707f5e3c0c66c170df8 (patch) | |
| tree | 36a50d847b90bf8108d2f00584a8abd154ce5780 /drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | |
| parent | f0511e66114a6414cfca92d7b94118913a0c11ff (diff) | |
| download | linux-stable-90e94b160c7f647ddffda707f5e3c0c66c170df8.tar.gz linux-stable-90e94b160c7f647ddffda707f5e3c0c66c170df8.tar.bz2 linux-stable-90e94b160c7f647ddffda707f5e3c0c66c170df8.zip | |
drm/amdgpu: Fix error handling in amdgpu_flip_work_func.
The patch e1d09dc0ccc6: "drm/amdgpu: Don't hang in
amdgpu_flip_work_func on disabled crtc." from Feb 19, 2016, leads to
the following static checker warning, as reported by Dan Carpenter in
https://lists.freedesktop.org/archives/dri-devel/2016-February/101987.html
drivers/gpu/drm/amd/amdgpu/amdgpu_display.c:127 amdgpu_flip_work_func() warn: should this be 'repcnt == -1'
drivers/gpu/drm/amd/amdgpu/amdgpu_display.c:136 amdgpu_flip_work_func() error: double unlock 'spin_lock:&crtc->dev->event_lock'
drivers/gpu/drm/amd/amdgpu/amdgpu_display.c:136 amdgpu_flip_work_func() error: double unlock 'irqsave:flags'
This patch fixes both reported problems:
Change post-decrement of repcnt to pre-decrement, so
it can't underflow anymore, but still performs up to
three repetitions - three is the maximum one could
expect in practice.
Move the spin_unlock_irqrestore to where it actually
belongs.
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Cc: <stable@vger.kernel.org> # 4.4+
Cc: Michel Dänzer <michel.daenzer@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_display.c')
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c index 8297bc319369..1846d65b7285 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c @@ -96,7 +96,7 @@ static void amdgpu_flip_work_func(struct work_struct *__work) * In practice this won't execute very often unless on very fast * machines because the time window for this to happen is very small. */ - while (amdgpuCrtc->enabled && repcnt--) { + while (amdgpuCrtc->enabled && --repcnt) { /* GET_DISTANCE_TO_VBLANKSTART returns distance to real vblank * start in hpos, and to the "fudged earlier" vblank start in * vpos. @@ -112,13 +112,13 @@ static void amdgpu_flip_work_func(struct work_struct *__work) break; /* Sleep at least until estimated real start of hw vblank */ - spin_unlock_irqrestore(&crtc->dev->event_lock, flags); min_udelay = (-hpos + 1) * max(vblank->linedur_ns / 1000, 5); if (min_udelay > vblank->framedur_ns / 2000) { /* Don't wait ridiculously long - something is wrong */ repcnt = 0; break; } + spin_unlock_irqrestore(&crtc->dev->event_lock, flags); usleep_range(min_udelay, 2 * min_udelay); spin_lock_irqsave(&crtc->dev->event_lock, flags); }; |