On 15/06/2022 19:24, Rob Clark wrote:
From: Rob Clark <robdclark@xxxxxxxxxxxx>
And while we are at it, let's start the fence counter close to the
rollover point so that if issues slip in, they are more obvious.
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
Should it also have
Fixes: fde5de6cb461 ("drm/msm: move fence code to it's own file")
Or maybe
Fixes: 5f3aee4ceb5b ("drm/msm: Handle fence rollover")
Otherwise:
Reviewed: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
drivers/gpu/drm/msm/msm_fence.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_fence.c b/drivers/gpu/drm/msm/msm_fence.c
index 3df255402a33..a35a6746c7cd 100644
--- a/drivers/gpu/drm/msm/msm_fence.c
+++ b/drivers/gpu/drm/msm/msm_fence.c
@@ -28,6 +28,14 @@ msm_fence_context_alloc(struct drm_device *dev, volatile uint32_t *fenceptr,
fctx->fenceptr = fenceptr;
spin_lock_init(&fctx->spinlock);
+ /*
+ * Start out close to the 32b fence rollover point, so we can
+ * catch bugs with fence comparisons.
+ */
+ fctx->last_fence = 0xffffff00;
+ fctx->completed_fence = fctx->last_fence;
+ *fctx->fenceptr = fctx->last_fence;
This looks like a debugging hack. But probably it's fine to have it, as
it wouldn't cause any side effects.
+
return fctx;
}
@@ -46,11 +54,12 @@ bool msm_fence_completed(struct msm_fence_context *fctx, uint32_t fence)
(int32_t)(*fctx->fenceptr - fence) >= 0;
}
-/* called from workqueue */
+/* called from irq handler */
void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence)
{
spin_lock(&fctx->spinlock);
- fctx->completed_fence = max(fence, fctx->completed_fence);
+ if (fence_after(fence, fctx->completed_fence))
+ fctx->completed_fence = fence;
spin_unlock(&fctx->spinlock);
}
--
With best wishes
Dmitry
