From b4142fc4d52d051d4d8df1fb6c569e5b445d369e Mon Sep 17 00:00:00 2001 From: Dmitry Vyukov Date: Sat, 20 Mar 2021 14:28:40 +0100 Subject: [PATCH] drm/vkms: fix misuse of WARN_ON 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 Reported-by: syzbot+4fc21a003c8332eb0bdd@syzkaller.appspotmail.com Cc: Rodrigo Siqueira Cc: Melissa Wen Cc: Haneen Mohammed Cc: Daniel Vetter Cc: David Airlie Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Acked-by: Melissa Wen Signed-off-by: Melissa Wen Link: https://patchwork.freedesktop.org/patch/msgid/20210320132840.1315853-1-dvyukov@google.com --- 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 6164349..57bbd32 100644 --- a/drivers/gpu/drm/vkms/vkms_crtc.c +++ b/drivers/gpu/drm/vkms/vkms_crtc.c @@ -22,7 +22,8 @@ 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); -- 2.7.4