From cff52e5fc4cfc978b7df898dc14a0492c7ef0ae8 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 18 Oct 2016 00:13:39 +0200 Subject: [PATCH] drm: avoid uninitialized timestamp use in wait_vblank gcc warns about the timestamp in drm_wait_vblank being possibly used without an initialization: drivers/gpu/drm/drm_irq.c: In function 'drm_crtc_send_vblank_event': drivers/gpu/drm/drm_irq.c:992:24: error: 'now.tv_usec' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/gpu/drm/drm_irq.c:1069:17: note: 'now.tv_usec' was declared here drivers/gpu/drm/drm_irq.c:991:23: error: 'now.tv_sec' may be used uninitialized in this function [-Werror=maybe-uninitialized] This can happen if drm_vblank_count_and_time() returns 0 in its error path. To sanitize the error case, I'm changing that function to return a zero timestamp when it fails. Fixes: e6ae8687a87b ("drm: idiot-proof vblank") Reviewed-by: David Herrmann Cc: Rob Clark Cc: Daniel Vetter Signed-off-by: Arnd Bergmann Reviewed-by: Mario Kleiner Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20161017221355.1861551-6-arnd@arndb.de --- drivers/gpu/drm/drm_irq.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index b969a64a1514..48a6167f5e7b 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -952,8 +952,10 @@ static u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe, u32 vblank_count; unsigned int seq; - if (WARN_ON(pipe >= dev->num_crtcs)) + if (WARN_ON(pipe >= dev->num_crtcs)) { + *vblanktime = (struct timeval) { 0 }; return 0; + } do { seq = read_seqbegin(&vblank->seqlock); -- 2.20.1