From 12fec62aea6ea67512f0ddabf960c9270b6d1b05 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 20 Sep 2018 21:05:30 +0100 Subject: [PATCH] drm: Fix syncobj handing of schedule() returning 0 After schedule() returns 0, we must do one last check of COND to determine the reason for the wakeup with 0 jiffies remaining before reporting the timeout -- otherwise we may lose the signal due to scheduler delays. References: https://bugs.freedesktop.org/show_bug.cgi?id=106690 Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20180920200530.2836-2-chris@chris-wilson.co.uk Reviewed-by: Daniel Vetter --- drivers/gpu/drm/drm_syncobj.c | 41 +++++++++++++++-------------------------- 1 file changed, 15 insertions(+), 26 deletions(-) diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index e254f97..5bcb3ef 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -672,7 +672,6 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs, { struct syncobj_wait_entry *entries; struct dma_fence *fence; - signed long ret; uint32_t signaled_count, i; entries = kcalloc(count, sizeof(*entries), GFP_KERNEL); @@ -692,7 +691,7 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs, if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) { continue; } else { - ret = -EINVAL; + timeout = -EINVAL; goto cleanup_entries; } } @@ -704,12 +703,6 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs, } } - /* Initialize ret to the max of timeout and 1. That way, the - * default return value indicates a successful wait and not a - * timeout. - */ - ret = max_t(signed long, timeout, 1); - if (signaled_count == count || (signaled_count > 0 && !(flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL))) @@ -760,18 +753,17 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs, goto done_waiting; if (timeout == 0) { - /* If we are doing a 0 timeout wait and we got - * here, then we just timed out. - */ - ret = 0; + timeout = -ETIME; goto done_waiting; } - ret = schedule_timeout(ret); + if (signal_pending(current)) { + timeout = -ERESTARTSYS; + goto done_waiting; + } - if (ret > 0 && signal_pending(current)) - ret = -ERESTARTSYS; - } while (ret > 0); + timeout = schedule_timeout(timeout); + } while (1); done_waiting: __set_current_state(TASK_RUNNING); @@ -788,7 +780,7 @@ cleanup_entries: } kfree(entries); - return ret; + return timeout; } /** @@ -829,19 +821,16 @@ static int drm_syncobj_array_wait(struct drm_device *dev, struct drm_syncobj **syncobjs) { signed long timeout = drm_timeout_abs_to_jiffies(wait->timeout_nsec); - signed long ret = 0; uint32_t first = ~0; - ret = drm_syncobj_array_wait_timeout(syncobjs, - wait->count_handles, - wait->flags, - timeout, &first); - if (ret < 0) - return ret; + timeout = drm_syncobj_array_wait_timeout(syncobjs, + wait->count_handles, + wait->flags, + timeout, &first); + if (timeout < 0) + return timeout; wait->first_signaled = first; - if (ret == 0) - return -ETIME; return 0; } -- 2.7.4