On Tue, Jul 06, 2021 at 11:14:01AM +0200, Daniel Vetter wrote:
On Tue, Jul 06, 2021 at 10:05:58AM +0100, Matthew Auld wrote:
It might be useful for drivers to annotate a path where hitting the actual wait path might be difficult or unlikely through normal testing.
Suggested-by: Daniel Vetter daniel.vetter@ffwll.ch Signed-off-by: Matthew Auld matthew.auld@intel.com Cc: Thomas Hellström thomas.hellstrom@linux.intel.com
drivers/dma-buf/dma-fence.c | 19 ++++++++++++++++--- include/linux/dma-fence.h | 2 ++ 2 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index ce0f5eff575d..f2cd036b5243 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -335,6 +335,21 @@ void __dma_fence_might_wait(void) } #endif
+/**
- dma_fence_might_wait - entering a section which might wait on DMA fence
- critical section.
- This is also potentially useful for drivers to call directly, when annotating
- a path where hitting the actual wait path might be difficult or unlikely
- through normal testing.
Maybe also add a
"See also dma_fence_begin_signalling() and dma_fence_end_signalling."
here and a similar note the these two functions pointing at dma_fence_might_wait()? I do like to link things together when there's a group of functions.
With that: Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch
Also ack for merging through drm-intel-gt-next, I don't think anything in drm-misc plans to use this anytime soon. But please add the dma-buf Cc: lines for the next round (dim add-missing-cc should cover you). -Daniel
- */
+void dma_fence_might_wait(void) +{
- might_sleep();
- __dma_fence_might_wait();
+} +EXPORT_SYMBOL(dma_fence_might_wait);
/**
- dma_fence_signal_timestamp_locked - signal completion of a fence
@@ -495,9 +510,7 @@ dma_fence_wait_timeout(struct dma_fence *fence, bool intr, signed long timeout) if (WARN_ON(timeout < 0)) return -EINVAL;
- might_sleep();
- __dma_fence_might_wait();
dma_fence_might_wait();
trace_dma_fence_wait_start(fence); if (fence->ops->wait)
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 6ffb4b2c6371..37bf4beed93f 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -370,6 +370,8 @@ static inline void dma_fence_end_signalling(bool cookie) {} static inline void __dma_fence_might_wait(void) {} #endif
+void dma_fence_might_wait(void);
int dma_fence_signal(struct dma_fence *fence); int dma_fence_signal_locked(struct dma_fence *fence); int dma_fence_signal_timestamp(struct dma_fence *fence, ktime_t timestamp); -- 2.26.3
-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch