| Message ID | 1470260019-6173-3-git-send-email-rodrigo.vivi@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
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(); - 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",
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(-)