Now we tackle the functions also called from interrupt handlers.
- intel_check_page_flip is exclusively called from irq handlers, so a plain spin_lock is all we need. In i915_irq.c we have the convention to give all such functions an _irq_handler postfix, but that would look strange and als be a bit a misleading name. I've opted for a WARN_ON(!in_irq()) instead.
- The other two places left are called both from interrupt handlers and from our reset work, so need the full irqsave dance. Annotate them with a short comment.
Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/i915/intel_display.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index dcbefe510a2a..d120dfff3841 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -9385,6 +9385,10 @@ static void do_intel_finish_page_flip(struct drm_device *dev, if (intel_crtc == NULL) return;
+ /* + * This is called both by irq handlers and the reset code (to complete + * lost pageflips) so needs the full irqsave spinlocks. + */ spin_lock_irqsave(&dev->event_lock, flags); work = intel_crtc->unpin_work;
@@ -9466,7 +9470,12 @@ void intel_prepare_page_flip(struct drm_device *dev, int plane) to_intel_crtc(dev_priv->plane_to_crtc_mapping[plane]); unsigned long flags;
- /* NB: An MMIO update of the plane base pointer will also + + /* + * This is called both by irq handlers and the reset code (to complete + * lost pageflips) so needs the full irqsave spinlocks. + * + * NB: An MMIO update of the plane base pointer will also * generate a page-flip completion irq, i.e. every modeset * is also accompanied by a spurious intel_prepare_page_flip(). */ @@ -9923,18 +9932,19 @@ void intel_check_page_flip(struct drm_device *dev, int pipe) struct drm_i915_private *dev_priv = dev->dev_private; struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe]; struct intel_crtc *intel_crtc = to_intel_crtc(crtc); - unsigned long flags; + + WARN_ON(!in_irq());
if (crtc == NULL) return;
- spin_lock_irqsave(&dev->event_lock, flags); + spin_lock(&dev->event_lock); if (intel_crtc->unpin_work && __intel_pageflip_stall_check(dev, crtc)) { WARN_ONCE(1, "Kicking stuck page flip: queued at %d, now %d\n", intel_crtc->unpin_work->flip_queued_vblank, drm_vblank_count(dev, pipe)); page_flip_completed(intel_crtc); } - spin_unlock_irqrestore(&dev->event_lock, flags); + spin_unlock(&dev->event_lock); }
static int intel_crtc_page_flip(struct drm_crtc *crtc,