The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 5b0112356cf9a735632b26ff5f3450e1716c8598 Mon Sep 17 00:00:00 2001 From: Chunming Zhou <David1.Zhou@xxxxxxx> Date: Thu, 10 Dec 2015 17:34:33 +0800 Subject: [PATCH] drm/amdgpu: restrict the sched jobs number to power of two MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Chunming Zhou <David1.Zhou@xxxxxxx> Reviewed-by: Christian König <christian.koenig@xxxxxxx> CC: stable@xxxxxxxxxxxxxxx diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c index ee121ec2917b..17d1fb12128a 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c @@ -252,7 +252,7 @@ uint64_t amdgpu_ctx_add_fence(struct amdgpu_ctx *ctx, struct amdgpu_ring *ring, unsigned idx = 0; struct fence *other = NULL; - idx = seq % amdgpu_sched_jobs; + idx = seq & (amdgpu_sched_jobs - 1); other = cring->fences[idx]; if (other) { signed long r; @@ -292,7 +292,7 @@ struct fence *amdgpu_ctx_get_fence(struct amdgpu_ctx *ctx, return NULL; } - fence = fence_get(cring->fences[seq % amdgpu_sched_jobs]); + fence = fence_get(cring->fences[seq & (amdgpu_sched_jobs - 1)]); spin_unlock(&ctx->ring_lock); return fence; diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index 54af6ce7901f..587ff7145361 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -949,6 +949,15 @@ static bool amdgpu_check_pot_argument(int arg) */ static void amdgpu_check_arguments(struct amdgpu_device *adev) { + if (amdgpu_sched_jobs < 4) { + dev_warn(adev->dev, "sched jobs (%d) must be at least 4\n", + amdgpu_sched_jobs); + amdgpu_sched_jobs = 4; + } else if (!amdgpu_check_pot_argument(amdgpu_sched_jobs)){ + dev_warn(adev->dev, "sched jobs (%d) must be a power of 2\n", + amdgpu_sched_jobs); + amdgpu_sched_jobs = roundup_pow_of_two(amdgpu_sched_jobs); + } /* vramlimit must be a power of two */ if (!amdgpu_check_pot_argument(amdgpu_vram_limit)) { dev_warn(adev->dev, "vram limit (%d) must be a power of 2\n", -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html