Fence signaling must be enabled to make sure that the dma_fence_is_signaled() function ever returns true. Since drivers and implementations sometimes mess this up, this ensures correct behaviour when DMABUF_DEBUG_ENABLE_SIGNALING is used during debugging. This should make any implementation bugs resulting in not signaled fences much more obvious.
Signed-off-by: Arvind Yadav Arvind.Yadav@amd.com ---
Changes in v1,v2 : 1- Addressing Christian's comment to replace CONFIG_DEBUG_WW_MUTEX_SLOWPATH instead of CONFIG_DEBUG_FS. 2- As per Christian's comment moving this patch at last so The version of this patch is also changed and previously it was [PATCH 1/4]
Changes in v3: 1 - Adding new config DMABUF_DEBUG_ENABLE_SIGNALING. 2 - Replace CONFIG_DEBUG_WW_MUTEX_SLOWPATH to new CONFIG_DMABUF_DEBUG_ENABLE_SIGNALING.
--- drivers/dma-buf/Kconfig | 7 +++++++ include/linux/dma-fence.h | 5 +++++ 2 files changed, 12 insertions(+)
diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig index e4dc53a36428..c991e6a51510 100644 --- a/drivers/dma-buf/Kconfig +++ b/drivers/dma-buf/Kconfig @@ -65,6 +65,13 @@ config DMABUF_SELFTESTS default n depends on DMA_SHARED_BUFFER
+config DMABUF_DEBUG_ENABLE_SIGNALING + bool "DMA Fence enable signaling debug checks" + default n + depends on DMA_SHARED_BUFFER + help + This option enables additional checks for software signaling of fence. + menuconfig DMABUF_HEAPS bool "DMA-BUF Userland Memory Heaps" select DMA_SHARED_BUFFER diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 775cdc0b4f24..01e1fa4d3cec 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -428,6 +428,11 @@ dma_fence_is_signaled_locked(struct dma_fence *fence) static inline bool dma_fence_is_signaled(struct dma_fence *fence) { +#ifdef CONFIG_DMABUF_DEBUG_ENABLE_SIGNALING + if (!test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &fence->flags)) + return false; +#endif + if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) return true;