The i915_request fence wait behaves differently for timeout = 0 compared to expected dma-fence behavior.
i915 behavior: - Unsignaled: -ETIME - Signaled: 0 (= timeout)
Expected: - Unsignaled: 0 - Signaled: 1
Signed-off-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com --- drivers/gpu/drm/i915/i915_request.c | 57 ++++++++++++++++++++++++----- drivers/gpu/drm/i915/i915_request.h | 5 +++ 2 files changed, 52 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 820a1f38b271..42cd17357771 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -96,9 +96,9 @@ static signed long i915_fence_wait(struct dma_fence *fence, bool interruptible, signed long timeout) { - return i915_request_wait(to_request(fence), - interruptible | I915_WAIT_PRIORITY, - timeout); + return i915_request_wait_timeout(to_request(fence), + interruptible | I915_WAIT_PRIORITY, + timeout); }
struct kmem_cache *i915_request_slab_cache(void) @@ -1857,23 +1857,27 @@ static void request_wait_wake(struct dma_fence *fence, struct dma_fence_cb *cb) }
/** - * i915_request_wait - wait until execution of request has finished + * i915_request_wait_timeout - wait until execution of request has finished * @rq: the request to wait upon * @flags: how to wait * @timeout: how long to wait in jiffies * - * i915_request_wait() waits for the request to be completed, for a + * i915_request_wait_timeout() waits for the request to be completed, for a * maximum of @timeout jiffies (with MAX_SCHEDULE_TIMEOUT implying an * unbounded wait). * * Returns the remaining time (in jiffies) if the request completed, which may - * be zero or -ETIME if the request is unfinished after the timeout expires. + * be zero if the request is unfinished after the timeout expires. + * If the timeout is 0, it will return 1 if the fence is signaled. + * * May return -EINTR is called with I915_WAIT_INTERRUPTIBLE and a signal is * pending before the request completes. + * + * NOTE: This function has the same wait semantics as dma-fence. */ -long i915_request_wait(struct i915_request *rq, - unsigned int flags, - long timeout) +long i915_request_wait_timeout(struct i915_request *rq, + unsigned int flags, + long timeout) { const int state = flags & I915_WAIT_INTERRUPTIBLE ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE; @@ -1883,7 +1887,7 @@ long i915_request_wait(struct i915_request *rq, GEM_BUG_ON(timeout < 0);
if (dma_fence_is_signaled(&rq->fence)) - return timeout; + return timeout ?: 1;
if (!timeout) return -ETIME; @@ -1992,6 +1996,39 @@ long i915_request_wait(struct i915_request *rq, return timeout; }
+/** + * i915_request_wait - wait until execution of request has finished + * @rq: the request to wait upon + * @flags: how to wait + * @timeout: how long to wait in jiffies + * + * i915_request_wait() waits for the request to be completed, for a + * maximum of @timeout jiffies (with MAX_SCHEDULE_TIMEOUT implying an + * unbounded wait). + * + * Returns the remaining time (in jiffies) if the request completed, which may + * be zero or -ETIME if the request is unfinished after the timeout expires. + * May return -EINTR is called with I915_WAIT_INTERRUPTIBLE and a signal is + * pending before the request completes. + * + * NOTE: This function behaves differently from dma-fence wait semantics for + * timeout = 0. It returns 0 on success, and -ETIME if not signaled. + */ +long i915_request_wait(struct i915_request *rq, + unsigned int flags, + long timeout) +{ + long ret = i915_request_wait_timeout(rq, flags, timeout); + + if (!ret) + return -ETIME; + + if (ret > 0 && !timeout) + return 0; + + return ret; +} + static int print_sched_attr(const struct i915_sched_attr *attr, char *buf, int x, int len) { diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h index dc359242d1ae..3c6e8acd1457 100644 --- a/drivers/gpu/drm/i915/i915_request.h +++ b/drivers/gpu/drm/i915/i915_request.h @@ -414,6 +414,11 @@ void i915_request_unsubmit(struct i915_request *request);
void i915_request_cancel(struct i915_request *rq, int error);
+long i915_request_wait_timeout(struct i915_request *rq, + unsigned int flags, + long timeout) + __attribute__((nonnull(1))); + long i915_request_wait(struct i915_request *rq, unsigned int flags, long timeout)