From: Rob Clark <[email protected]>
I noticed while looking at some traces, that we could miss calls to
msm_update_fence(), as the irq could have raced with retire_submits()
which could have already popped the last submit on a ring out of the
queue of in-flight submits. But walking the list of submits in the
irq handler isn't really needed, as dma_fence_is_signaled() will dtrt.
So lets just drop it entirely.
Reported-by: Steev Klimaszewski <[email protected]>
Fixes: 95d1deb02a9c ("drm/msm/gem: Add fenced vma unpin")
Signed-off-by: Rob Clark <[email protected]>
---
drivers/gpu/drm/msm/msm_gpu.c | 22 ++--------------------
1 file changed, 2 insertions(+), 20 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index e59a757578df..b61078f0cd0f 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -176,24 +176,6 @@ int msm_gpu_hw_init(struct msm_gpu *gpu)
return ret;
}
-static void update_fences(struct msm_gpu *gpu, struct msm_ringbuffer *ring,
- uint32_t fence)
-{
- struct msm_gem_submit *submit;
- unsigned long flags;
-
- spin_lock_irqsave(&ring->submit_lock, flags);
- list_for_each_entry(submit, &ring->submits, node) {
- if (fence_after(submit->seqno, fence))
- break;
-
- msm_update_fence(submit->ring->fctx,
- submit->hw_fence->seqno);
- dma_fence_signal(submit->hw_fence);
- }
- spin_unlock_irqrestore(&ring->submit_lock, flags);
-}
-
#ifdef CONFIG_DEV_COREDUMP
static ssize_t msm_gpu_devcoredump_read(char *buffer, loff_t offset,
size_t count, void *data, size_t datalen)
@@ -450,7 +432,7 @@ static void recover_worker(struct kthread_work *work)
if (ring == cur_ring)
fence++;
- update_fences(gpu, ring, fence);
+ msm_update_fence(ring->fctx, fence);
}
if (msm_gpu_active(gpu)) {
@@ -753,7 +735,7 @@ void msm_gpu_retire(struct msm_gpu *gpu)
int i;
for (i = 0; i < gpu->nr_rings; i++)
- update_fences(gpu, gpu->rb[i], gpu->rb[i]->memptrs->fence);
+ msm_update_fence(gpu->rb[i]->fctx, gpu->rb[i]->memptrs->fence);
kthread_queue_work(gpu->worker, &gpu->retire_work);
update_sw_cntrs(gpu);
--
2.36.1
From: Rob Clark <[email protected]>
Prior to the last commit, this could result in setting the GPU
written fence value back to an older value, if we had missed
updating completed_fence prior to suspend. This was mostly
harmless as the GPU would eventually overwrite it again with
the correct value. But we should just not do this. Instead
just leave a sanity check that the fence looks plausible (in
case the GPU scribbled on memory).
Reported-by: Steev Klimaszewski <[email protected]>
Fixes: 95d1deb02a9c ("drm/msm/gem: Add fenced vma unpin")
Signed-off-by: Rob Clark <[email protected]>
---
drivers/gpu/drm/msm/adreno/adreno_gpu.c | 11 ++++++++---
drivers/gpu/drm/msm/msm_gpu.c | 2 +-
2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index e1aef4875e2f..dd044d557c7c 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -498,10 +498,15 @@ int adreno_hw_init(struct msm_gpu *gpu)
ring->cur = ring->start;
ring->next = ring->start;
-
- /* reset completed fence seqno: */
- ring->memptrs->fence = ring->fctx->completed_fence;
ring->memptrs->rptr = 0;
+
+ /* Detect and clean up an impossible fence, ie. if GPU managed
+ * to scribble something invalid, we don't want that to confuse
+ * us into mistakingly believing that submits have completed.
+ */
+ if (fence_before(ring->fctx->last_fence, ring->memptrs->fence)) {
+ ring->memptrs->fence = ring->fctx->last_fence;
+ }
}
return 0;
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index b61078f0cd0f..8c00f9187c03 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -430,7 +430,7 @@ static void recover_worker(struct kthread_work *work)
* one more to clear the faulting submit
*/
if (ring == cur_ring)
- fence++;
+ ring->memptrs->fence = ++fence;
msm_update_fence(ring->fctx, fence);
}
--
2.36.1
On 6/15/22 10:01 AM, Rob Clark wrote:
> From: Rob Clark <[email protected]>
>
> I noticed while looking at some traces, that we could miss calls to
> msm_update_fence(), as the irq could have raced with retire_submits()
> which could have already popped the last submit on a ring out of the
> queue of in-flight submits. But walking the list of submits in the
> irq handler isn't really needed, as dma_fence_is_signaled() will dtrt.
> So lets just drop it entirely.
>
> Reported-by: Steev Klimaszewski <[email protected]>
> Fixes: 95d1deb02a9c ("drm/msm/gem: Add fenced vma unpin")
> Signed-off-by: Rob Clark <[email protected]>
> ---
> drivers/gpu/drm/msm/msm_gpu.c | 22 ++--------------------
> 1 file changed, 2 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> index e59a757578df..b61078f0cd0f 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.c
> +++ b/drivers/gpu/drm/msm/msm_gpu.c
> @@ -176,24 +176,6 @@ int msm_gpu_hw_init(struct msm_gpu *gpu)
> return ret;
> }
>
> -static void update_fences(struct msm_gpu *gpu, struct msm_ringbuffer *ring,
> - uint32_t fence)
> -{
> - struct msm_gem_submit *submit;
> - unsigned long flags;
> -
> - spin_lock_irqsave(&ring->submit_lock, flags);
> - list_for_each_entry(submit, &ring->submits, node) {
> - if (fence_after(submit->seqno, fence))
> - break;
> -
> - msm_update_fence(submit->ring->fctx,
> - submit->hw_fence->seqno);
> - dma_fence_signal(submit->hw_fence);
> - }
> - spin_unlock_irqrestore(&ring->submit_lock, flags);
> -}
> -
> #ifdef CONFIG_DEV_COREDUMP
> static ssize_t msm_gpu_devcoredump_read(char *buffer, loff_t offset,
> size_t count, void *data, size_t datalen)
> @@ -450,7 +432,7 @@ static void recover_worker(struct kthread_work *work)
> if (ring == cur_ring)
> fence++;
>
> - update_fences(gpu, ring, fence);
> + msm_update_fence(ring->fctx, fence);
> }
>
> if (msm_gpu_active(gpu)) {
> @@ -753,7 +735,7 @@ void msm_gpu_retire(struct msm_gpu *gpu)
> int i;
>
> for (i = 0; i < gpu->nr_rings; i++)
> - update_fences(gpu, gpu->rb[i], gpu->rb[i]->memptrs->fence);
> + msm_update_fence(gpu->rb[i]->fctx, gpu->rb[i]->memptrs->fence);
>
> kthread_queue_work(gpu->worker, &gpu->retire_work);
> update_sw_cntrs(gpu);
Tested on the Lenovo Yoga C630
Tested-by: Steev Klimaszewski <[email protected]>
On 6/15/22 10:01 AM, Rob Clark wrote:
> From: Rob Clark <[email protected]>
>
> Prior to the last commit, this could result in setting the GPU
> written fence value back to an older value, if we had missed
> updating completed_fence prior to suspend. This was mostly
> harmless as the GPU would eventually overwrite it again with
> the correct value. But we should just not do this. Instead
> just leave a sanity check that the fence looks plausible (in
> case the GPU scribbled on memory).
>
> Reported-by: Steev Klimaszewski <[email protected]>
> Fixes: 95d1deb02a9c ("drm/msm/gem: Add fenced vma unpin")
> Signed-off-by: Rob Clark <[email protected]>
> ---
> drivers/gpu/drm/msm/adreno/adreno_gpu.c | 11 ++++++++---
> drivers/gpu/drm/msm/msm_gpu.c | 2 +-
> 2 files changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> index e1aef4875e2f..dd044d557c7c 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> @@ -498,10 +498,15 @@ int adreno_hw_init(struct msm_gpu *gpu)
>
> ring->cur = ring->start;
> ring->next = ring->start;
> -
> - /* reset completed fence seqno: */
> - ring->memptrs->fence = ring->fctx->completed_fence;
> ring->memptrs->rptr = 0;
> +
> + /* Detect and clean up an impossible fence, ie. if GPU managed
> + * to scribble something invalid, we don't want that to confuse
> + * us into mistakingly believing that submits have completed.
> + */
> + if (fence_before(ring->fctx->last_fence, ring->memptrs->fence)) {
> + ring->memptrs->fence = ring->fctx->last_fence;
> + }
> }
>
> return 0;
> diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> index b61078f0cd0f..8c00f9187c03 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.c
> +++ b/drivers/gpu/drm/msm/msm_gpu.c
> @@ -430,7 +430,7 @@ static void recover_worker(struct kthread_work *work)
> * one more to clear the faulting submit
> */
> if (ring == cur_ring)
> - fence++;
> + ring->memptrs->fence = ++fence;
>
> msm_update_fence(ring->fctx, fence);
> }
Tested on the Lenovo Yoga C630
Tested-by: Steev Klimaszewski <[email protected]>