On Thu, 08 Dec 2011 18:35:24 -0800
Eric Anholt <eric at anholt.net> wrote:
> Since MI_FLUSH_DW exists on gen6, and keithp says we still have
> outstanding issues with missed blit IRQs there, I started trying it
> today. Two kernel branches posted at
> git://people.freedesktop.org/~anholt/linux/
>
> flush-dw-notify: This is the initial attempt I did with MI_FLUSH_DW with
> internal notify. Quickly produced missed blit IRQs. I thought this was
> because the notify was in parallel with the post-sync op, not synced to
> be after. So I reverted part of the patch and produced...
Bummer, that one looks like it ought to work.
On current drm-intel-next, this patch seems to be preventing missed
IRQs on IVB at least. Anyone else wanna give it a try and confirm?
I've only tested with Eric's blit-and-wait.c test so far.
--
Jesse Barnes, Intel Open Source Technology Center
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index b40004b..cb821a0 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -482,78 +482,83 @@ static irqreturn_t ivybridge_irq_handler(DRM_IRQ_ARGS)
I915_WRITE(DEIER, de_ier & ~DE_MASTER_IRQ_CONTROL);
POSTING_READ(DEIER);
- de_iir = I915_READ(DEIIR);
- gt_iir = I915_READ(GTIIR);
- pch_iir = I915_READ(SDEIIR);
- pm_iir = I915_READ(GEN6_PMIIR);
+ /*
+ * Try to mitigate dropped IRQs by handling as many as possible
+ * each time we get a physical interrupt.
+ */
+ while (1) {
+ de_iir = I915_READ(DEIIR);
+ gt_iir = I915_READ(GTIIR);
+ pch_iir = I915_READ(SDEIIR);
+ pm_iir = I915_READ(GEN6_PMIIR);
+
+ if (de_iir == 0 && gt_iir == 0 && pch_iir == 0 && pm_iir == 0) {
+ I915_WRITE(DEIER, de_ier);
+ POSTING_READ(DEIER);
+ return ret;
+ }
- if (de_iir == 0 && gt_iir == 0 && pch_iir == 0 && pm_iir == 0)
- goto done;
+ ret = IRQ_HANDLED;
- ret = IRQ_HANDLED;
+ if (dev->primary->master) {
+ master_priv = dev->primary->master->driver_priv;
+ if (master_priv->sarea_priv)
+ master_priv->sarea_priv->last_dispatch =
+ READ_BREADCRUMB(dev_priv);
+ }
- if (dev->primary->master) {
- master_priv = dev->primary->master->driver_priv;
- if (master_priv->sarea_priv)
- master_priv->sarea_priv->last_dispatch =
- READ_BREADCRUMB(dev_priv);
- }
+ if (gt_iir & (GT_USER_INTERRUPT | GT_PIPE_NOTIFY))
+ notify_ring(dev, &dev_priv->ring[RCS]);
+ if (gt_iir & GT_GEN6_BSD_USER_INTERRUPT)
+ notify_ring(dev, &dev_priv->ring[VCS]);
+ if (gt_iir & GT_BLT_USER_INTERRUPT)
+ notify_ring(dev, &dev_priv->ring[BCS]);
- if (gt_iir & (GT_USER_INTERRUPT | GT_PIPE_NOTIFY))
- notify_ring(dev, &dev_priv->ring[RCS]);
- if (gt_iir & GT_GEN6_BSD_USER_INTERRUPT)
- notify_ring(dev, &dev_priv->ring[VCS]);
- if (gt_iir & GT_BLT_USER_INTERRUPT)
- notify_ring(dev, &dev_priv->ring[BCS]);
+ if (de_iir & DE_GSE_IVB)
+ intel_opregion_gse_intr(dev);
- if (de_iir & DE_GSE_IVB)
- intel_opregion_gse_intr(dev);
+ if (de_iir & DE_PLANEA_FLIP_DONE_IVB) {
+ intel_prepare_page_flip(dev, 0);
+ intel_finish_page_flip_plane(dev, 0);
+ }
- if (de_iir & DE_PLANEA_FLIP_DONE_IVB) {
- intel_prepare_page_flip(dev, 0);
- intel_finish_page_flip_plane(dev, 0);
- }
+ if (de_iir & DE_PLANEB_FLIP_DONE_IVB) {
+ intel_prepare_page_flip(dev, 1);
+ intel_finish_page_flip_plane(dev, 1);
+ }
- if (de_iir & DE_PLANEB_FLIP_DONE_IVB) {
- intel_prepare_page_flip(dev, 1);
- intel_finish_page_flip_plane(dev, 1);
- }
+ if (de_iir & DE_PIPEA_VBLANK_IVB)
+ drm_handle_vblank(dev, 0);
- if (de_iir & DE_PIPEA_VBLANK_IVB)
- drm_handle_vblank(dev, 0);
+ if (de_iir & DE_PIPEB_VBLANK_IVB)
+ drm_handle_vblank(dev, 1);
- if (de_iir & DE_PIPEB_VBLANK_IVB)
- drm_handle_vblank(dev, 1);
+ /* check event from PCH */
+ if (de_iir & DE_PCH_EVENT_IVB) {
+ if (pch_iir & SDE_HOTPLUG_MASK_CPT)
+ queue_work(dev_priv->wq,
+ &dev_priv->hotplug_work);
+ pch_irq_handler(dev);
+ }
- /* check event from PCH */
- if (de_iir & DE_PCH_EVENT_IVB) {
- if (pch_iir & SDE_HOTPLUG_MASK_CPT)
- queue_work(dev_priv->wq, &dev_priv->hotplug_work);
- pch_irq_handler(dev);
- }
+ if (pm_iir & GEN6_PM_DEFERRED_EVENTS) {
+ unsigned long flags;
+ spin_lock_irqsave(&dev_priv->rps_lock, flags);
+ WARN(dev_priv->pm_iir & pm_iir,
+ "Missed a PM interrupt\n");
+ dev_priv->pm_iir |= pm_iir;
+ I915_WRITE(GEN6_PMIMR, dev_priv->pm_iir);
+ POSTING_READ(GEN6_PMIMR);
+ spin_unlock_irqrestore(&dev_priv->rps_lock, flags);
+ queue_work(dev_priv->wq, &dev_priv->rps_work);
+ }
- if (pm_iir & GEN6_PM_DEFERRED_EVENTS) {
- unsigned long flags;
- spin_lock_irqsave(&dev_priv->rps_lock, flags);
- WARN(dev_priv->pm_iir & pm_iir, "Missed a PM interrupt\n");
- dev_priv->pm_iir |= pm_iir;
- I915_WRITE(GEN6_PMIMR, dev_priv->pm_iir);
- POSTING_READ(GEN6_PMIMR);
- spin_unlock_irqrestore(&dev_priv->rps_lock, flags);
- queue_work(dev_priv->wq, &dev_priv->rps_work);
+ /* should clear PCH hotplug event before clear CPU irq */
+ I915_WRITE(SDEIIR, pch_iir);
+ I915_WRITE(GTIIR, gt_iir);
+ I915_WRITE(DEIIR, de_iir);
+ I915_WRITE(GEN6_PMIIR, pm_iir);
}
-
- /* should clear PCH hotplug event before clear CPU irq */
- I915_WRITE(SDEIIR, pch_iir);
- I915_WRITE(GTIIR, gt_iir);
- I915_WRITE(DEIIR, de_iir);
- I915_WRITE(GEN6_PMIIR, pm_iir);
-
-done:
- I915_WRITE(DEIER, de_ier);
- POSTING_READ(DEIER);
-
- return ret;
}
static irqreturn_t ironlake_irq_handler(DRM_IRQ_ARGS)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index ca70e2f..a9bdcd6 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1301,9 +1301,11 @@ gen6_bsd_ring_get_irq(struct intel_ring_buffer *ring)
static void
gen6_bsd_ring_put_irq(struct intel_ring_buffer *ring)
{
+#if 0
return gen6_ring_put_irq(ring,
GT_GEN6_BSD_USER_INTERRUPT,
GEN6_BSD_USER_INTERRUPT);
+#endif
}
/* ring buffer for Video Codec for Gen6+ */
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