All of lore.kernel.org
 help / color / mirror / Atom feed
* [Intel-gfx] [CI 1/3] drm/i915: Remove livelock from "do_idle_maps" vtd w/a
@ 2020-12-09 16:40 Chris Wilson
  2020-12-09 16:40 ` [Intel-gfx] [CI 2/3] drm/i915: Sleep around performing iommu unmaps on Tigerlake Chris Wilson
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: Chris Wilson @ 2020-12-09 16:40 UTC (permalink / raw)
  To: intel-gfx

A call to wait for the GT to idle from inside the put_pages fallback is
prone to cause an uninterruptible livelock. As it does not provide
adequate serialisation with new requests, simply fallback to a trivial
sleep.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index c5ee1567f3d1..3ee2f682eff6 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -55,22 +55,17 @@ int i915_gem_gtt_prepare_pages(struct drm_i915_gem_object *obj,
 void i915_gem_gtt_finish_pages(struct drm_i915_gem_object *obj,
 			       struct sg_table *pages)
 {
-	struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
-	struct device *kdev = &dev_priv->drm.pdev->dev;
-	struct i915_ggtt *ggtt = &dev_priv->ggtt;
-
-	if (unlikely(ggtt->do_idle_maps)) {
-		/* XXX This does not prevent more requests being submitted! */
-		if (intel_gt_retire_requests_timeout(ggtt->vm.gt,
-						     -MAX_SCHEDULE_TIMEOUT)) {
-			drm_err(&dev_priv->drm,
-				"Failed to wait for idle; VT'd may hang.\n");
-			/* Wait a bit, in hopes it avoids the hang */
-			udelay(10);
-		}
-	}
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	struct i915_ggtt *ggtt = &i915->ggtt;
+
+	/* XXX This does not prevent more requests being submitted! */
+	if (unlikely(ggtt->do_idle_maps))
+		/* Wait a bit, in the hope it avoids the hang */
+		usleep_range(100, 250);
 
-	dma_unmap_sg(kdev, pages->sgl, pages->nents, PCI_DMA_BIDIRECTIONAL);
+	dma_unmap_sg(&i915->drm.pdev->dev,
+		     pages->sgl, pages->nents,
+		     PCI_DMA_BIDIRECTIONAL);
 }
 
 /**
-- 
2.20.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2020-12-09 19:31 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-12-09 16:40 [Intel-gfx] [CI 1/3] drm/i915: Remove livelock from "do_idle_maps" vtd w/a Chris Wilson
2020-12-09 16:40 ` [Intel-gfx] [CI 2/3] drm/i915: Sleep around performing iommu unmaps on Tigerlake Chris Wilson
2020-12-09 16:40 ` [Intel-gfx] [CI 3/3] drm/i915/gt: Remove uninterruptible parameter from intel_gt_wait_for_idle Chris Wilson
2020-12-09 17:49 ` [Intel-gfx] ✓ Fi.CI.BAT: success for series starting with [CI,1/3] drm/i915: Remove livelock from "do_idle_maps" vtd w/a Patchwork
2020-12-09 19:30 ` [Intel-gfx] ✓ Fi.CI.IGT: " Patchwork

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.