[PATCH 1/2] drm/msm: Drop update_fences()

From: Rob Clark
Date: Wed Jun 15 2022 - 11:01:05 EST


From: Rob Clark <robdclark@xxxxxxxxxxxx>

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 <steev@xxxxxxxx>
Fixes: 95d1deb02a9c ("drm/msm/gem: Add fenced vma unpin")
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
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