Commit 5f3aee4c authored by Rob Clark's avatar Rob Clark
Browse files

drm/msm: Handle fence rollover 



Add some helpers for fence comparision, which handle rollover properly,
and stop open coding fence seqno comparisions.

Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
Reviewed-by: default avatarAkhil P Oommen <akhilpo@codeaurora.org>
Link: https://lore.kernel.org/r/20211109181117.591148-5-robdclark@gmail.com


Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
parent c28e2f2b

drivers/gpu/drm/msm/msm_drv.c

+1 −1
Original line number Diff line number Diff line
@@ -967,7 +967,7 @@ static int wait_fence(struct msm_gpu_submitqueue *queue, uint32_t fence_id, 
	struct dma_fence *fence;

	int ret;



	if (fence_id > queue->last_fence) {

	if (fence_after(fence_id, queue->last_fence)) {

		DRM_ERROR_RATELIMITED("waiting on invalid fence: %u (of %u)\n",

				      fence_id, queue->last_fence);

		return -EINVAL;

drivers/gpu/drm/msm/msm_fence.h

+12 −0
Original line number Diff line number Diff line
@@ -60,4 +60,16 @@ void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence); 


struct dma_fence * msm_fence_alloc(struct msm_fence_context *fctx);



static inline bool

fence_before(uint32_t a, uint32_t b)

{

   return (int32_t)(a - b) < 0;

}



static inline bool

fence_after(uint32_t a, uint32_t b)

{

   return (int32_t)(a - b) > 0;

}



#endif

drivers/gpu/drm/msm/msm_gpu.c

+3 −3
Original line number Diff line number Diff line
@@ -172,7 +172,7 @@ static void update_fences(struct msm_gpu *gpu, struct msm_ringbuffer *ring, 


	spin_lock_irqsave(&ring->submit_lock, flags);

	list_for_each_entry(submit, &ring->submits, node) {

		if (submit->seqno > fence)

		if (fence_after(submit->seqno, fence))

			break;



		msm_update_fence(submit->ring->fctx,
@@ -509,7 +509,7 @@ static void hangcheck_handler(struct timer_list *t) 
	if (fence != ring->hangcheck_fence) {

		/* some progress has been made.. ya! */

		ring->hangcheck_fence = fence;

	} else if (fence < ring->seqno) {

	} else if (fence_before(fence, ring->seqno)) {

		/* no progress and not done.. hung! */

		ring->hangcheck_fence = fence;

		DRM_DEV_ERROR(dev->dev, "%s: hangcheck detected gpu lockup rb %d!\n",
@@ -523,7 +523,7 @@ static void hangcheck_handler(struct timer_list *t) 
	}



	/* if still more pending work, reset the hangcheck timer: */

	if (ring->seqno > ring->hangcheck_fence)

	if (fence_after(ring->seqno, ring->hangcheck_fence))

		hangcheck_timer_reset(gpu);



	/* workaround for missing irq: */

drivers/gpu/drm/msm/msm_gpu.h

+1 −1
Original line number Diff line number Diff line
@@ -262,7 +262,7 @@ static inline bool msm_gpu_active(struct msm_gpu *gpu) 
	for (i = 0; i < gpu->nr_rings; i++) {

		struct msm_ringbuffer *ring = gpu->rb[i];



		if (ring->seqno > ring->memptrs->fence)

		if (fence_after(ring->seqno, ring->memptrs->fence))

			return true;

	}