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@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
---
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
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