From: Dmitry Vyukov <dvyukov@xxxxxxxxxx> [ Upstream commit b4142fc4d52d051d4d8df1fb6c569e5b445d369e ] vkms_vblank_simulate() uses WARN_ON for timing-dependent condition (timer overrun). This is a mis-use of WARN_ON, WARN_ON must be used to denote kernel bugs. Use pr_warn() instead. Signed-off-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Reported-by: syzbot+4fc21a003c8332eb0bdd@xxxxxxxxxxxxxxxxxxxxxxxxx Cc: Rodrigo Siqueira <rodrigosiqueiramelo@xxxxxxxxx> Cc: Melissa Wen <melissa.srw@xxxxxxxxx> Cc: Haneen Mohammed <hamohammed.sa@xxxxxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: David Airlie <airlied@xxxxxxxx> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Acked-by: Melissa Wen <melissa.srw@xxxxxxxxx> Signed-off-by: Melissa Wen <melissa.srw@xxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20210320132840.1315853-1-dvyukov@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/gpu/drm/vkms/vkms_crtc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c index 09c012d54d58..1ae5cd47d954 100644 --- a/drivers/gpu/drm/vkms/vkms_crtc.c +++ b/drivers/gpu/drm/vkms/vkms_crtc.c @@ -18,7 +18,8 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer) ret_overrun = hrtimer_forward_now(&output->vblank_hrtimer, output->period_ns); - WARN_ON(ret_overrun != 1); + if (ret_overrun != 1) + pr_warn("%s: vblank timer overrun\n", __func__); spin_lock(&output->lock); ret = drm_crtc_handle_vblank(crtc); -- 2.30.2