[PATCH v2 3/3] drm/syncobj: call might_sleep before waiting for fence submission

[Erik Kurzinger]

If either the DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT or
DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE flags are passed to
drm_syncobj_array_wait_timeout, the function might sleep if the fence at
one of the given timeline points has not yet been submitted. Therefore,
we should call might_sleep in that case to catch potential bugs.

Signed-off-by: Erik Kurzinger <ekurzin...@nvidia.com>
---
 drivers/gpu/drm/drm_syncobj.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
index c59bb02e2c07..e04965878a08 100644
--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -1062,8 +1062,10 @@ static signed long drm_syncobj_array_wait_timeout(struct 
drm_syncobj **syncobjs,
        uint32_t signaled_count, i;
 
        if (flags & (DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
-                    DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE))
+                    DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) {
+               might_sleep();
                lockdep_assert_none_held_once();
+       }
 
        points = kmalloc_array(count, sizeof(*points), GFP_KERNEL);
        if (points == NULL)
-- 
2.43.0