On Wed, Aug 03, 2016 at 02:33:35PM -0700, Rodrigo Vivi wrote:
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.
Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com
drivers/gpu/drm/i915/intel_sprite.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c index 0de935a..d8bc27c 100644 --- a/drivers/gpu/drm/i915/intel_sprite.c +++ b/drivers/gpu/drm/i915/intel_sprite.c @@ -94,14 +94,14 @@ 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) return;
if (WARN_ON(drm_crtc_vblank_get(&crtc->base))) return;
- local_irq_disable();
- crtc->debug.min_vbl = min; crtc->debug.max_vbl = max; trace_i915_pipe_update_start(crtc);
@@ -166,6 +166,8 @@ void intel_pipe_update_end(struct intel_crtc *crtc, struct intel_flip_work *work
trace_i915_pipe_update_end(crtc, end_vbl_count, scanline_end);
- local_irq_enable();
- /* We're still in the vblank-evade critical section, this can't race.
- Would be slightly nice to just grab the vblank count and arm the
- event outside of the critical section - the spinlock might spin for a
@@ -180,8 +182,6 @@ void intel_pipe_update_end(struct intel_crtc *crtc, struct intel_flip_work *work crtc->base.state->event = NULL; }
- local_irq_enable();
You can't do this. Pls reaad the comment right above why.
What we need here is a drm_crtc_vblank_get_noresume() or similar which will fail very loudly if the vblank refcount is 0. _noresume since that mirroros runtime PM, but it's a really bad name. -Daniel
- if (crtc->debug.start_vbl_count && crtc->debug.start_vbl_count != end_vbl_count) { DRM_ERROR("Atomic update failure on pipe %c (start=%u end=%u) time %lld us, min %d, max %d, scanline start %d, end %d\n",
-- 2.4.3
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