From: Rob Clark <robdcl...@chromium.org> The CP_SMMU_TABLE_UPDATE _should_ be waiting for idle, but on some devices (x1-85, possibly others), it seems to pass that barrier while there are still things in the event completion FIFO waiting to be written back to memory.
Work around that by adding a fence wait before context switch. The CP_EVENT_WRITE that writes the fence is the last write from a submit, so seeing this value hit memory is a reliable indication that it is safe to proceed with the context switch. Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/63 Signed-off-by: Rob Clark <robdcl...@chromium.org> --- drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c index bcaec86ac67a..ba5b35502e6d 100644 --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c @@ -101,9 +101,10 @@ static void get_stats_counter(struct msm_ringbuffer *ring, u32 counter, } static void a6xx_set_pagetable(struct a6xx_gpu *a6xx_gpu, - struct msm_ringbuffer *ring, struct msm_file_private *ctx) + struct msm_ringbuffer *ring, struct msm_gem_submit *submit) { bool sysprof = refcount_read(&a6xx_gpu->base.base.sysprof_active) > 1; + struct msm_file_private *ctx = submit->queue->ctx; struct adreno_gpu *adreno_gpu = &a6xx_gpu->base; phys_addr_t ttbr; u32 asid; @@ -115,6 +116,13 @@ static void a6xx_set_pagetable(struct a6xx_gpu *a6xx_gpu, if (msm_iommu_pagetable_params(ctx->aspace->mmu, &ttbr, &asid)) return; + /* Wait for previous submit to complete before continuing: */ + OUT_PKT7(ring, CP_WAIT_TIMESTAMP, 4); + OUT_RING(ring, 0); + OUT_RING(ring, lower_32_bits(rbmemptr(ring, fence))); + OUT_RING(ring, upper_32_bits(rbmemptr(ring, fence))); + OUT_RING(ring, submit->seqno - 1); + if (!sysprof) { if (!adreno_is_a7xx(adreno_gpu)) { /* Turn off protected mode to write to special registers */ @@ -193,7 +201,7 @@ static void a6xx_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit) struct msm_ringbuffer *ring = submit->ring; unsigned int i, ibs = 0; - a6xx_set_pagetable(a6xx_gpu, ring, submit->queue->ctx); + a6xx_set_pagetable(a6xx_gpu, ring, submit); get_stats_counter(ring, REG_A6XX_RBBM_PERFCTR_CP(0), rbmemptr_stats(ring, index, cpcycles_start)); @@ -283,7 +291,7 @@ static void a7xx_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit) OUT_PKT7(ring, CP_THREAD_CONTROL, 1); OUT_RING(ring, CP_THREAD_CONTROL_0_SYNC_THREADS | CP_SET_THREAD_BR); - a6xx_set_pagetable(a6xx_gpu, ring, submit->queue->ctx); + a6xx_set_pagetable(a6xx_gpu, ring, submit); get_stats_counter(ring, REG_A7XX_RBBM_PERFCTR_CP(0), rbmemptr_stats(ring, index, cpcycles_start)); -- 2.46.0
