From: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
drm_crtc_vblank_get call the drm_vblank_prepare that will be used soon
to control power saving states or anything else that needs a mutex
before the vblank happens.
local_irq_disable disables kernel preemption so we won't be able
to use mutex inside drm_crtc_vblank_get. For this reason we need
to move the drm_crtc_vblank_get a little up before disabling the
interruptions.
Another option would be to use local_irq_enable + local_irq_disable
around the drm_crtc_vblank_get, but let's avoid touching the kernel
states if we can call the vblank_get a bit earlier.
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
---
drivers/gpu/drm/i915/intel_sprite.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 97b1a54..3351c7e 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -94,13 +94,15 @@ void intel_pipe_update_start(struct intel_crtc *crtc)
min = vblank_start - usecs_to_scanlines(adjusted_mode, 100);
max = vblank_start - 1;
- local_irq_disable();
-
- if (min <= 0 || max <= 0)
+ if (WARN_ON(drm_crtc_vblank_get(&crtc->base)))
return;
- if (WARN_ON(drm_crtc_vblank_get(&crtc->base)))
+ local_irq_disable();
+
+ if (min <= 0 || max <= 0) {
+ drm_crtc_vblank_put(&crtc->base);
return;
+ }
crtc->debug.min_vbl = min;
crtc->debug.max_vbl = max;
--
2.5.0
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