From a111fbc4c44d2981f1a8fef64418685be5e30280 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Mon, 23 Oct 2017 18:25:40 +0300 Subject: [PATCH] drm/vblank: Tune drm_crtc_accurate_vblank_count() WARN down to a debug MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Since commit 632c6e4edef1 ("drm/vblank: Fix flip event vblank count") even drivers that don't implement accurate vblank timestamps will end up using drm_crtc_accurate_vblank_count(). That leads to a WARN every time drm_crtc_arm_vblank_event() gets called. The could be as often as every frame for each active crtc. Considering drm_crtc_accurate_vblank_count() is never any worse than the drm_vblank_count() we used previously, let's just skip the WARN unless DRM_UT_VBL is enabled. That way people won't be bothered by this unless they're debugging vblank code. And let's also change it to WARN_ONCE() so that even when you're debugging vblank code you won't get drowned by constant WARNs. Cc: stable@vger.kernel.org Cc: Daniel Vetter Cc: "Szyprowski, Marek" Cc: Andrzej Hajda Reported-by: Andrzej Hajda Fixes: 632c6e4edef1 ("drm/vblank: Fix flip event vblank count") Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20171023152540.15364-1-ville.syrjala@linux.intel.com Acked-by: Benjamin Gaignard Reviewed-by: Daniel Vetter --- drivers/gpu/drm/drm_vblank.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index 57cc6e37c810..09c1c4ff93ca 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -299,8 +299,8 @@ u32 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc) u32 vblank; unsigned long flags; - WARN(!dev->driver->get_vblank_timestamp, - "This function requires support for accurate vblank timestamps."); + WARN_ONCE(drm_debug & DRM_UT_VBL && !dev->driver->get_vblank_timestamp, + "This function requires support for accurate vblank timestamps."); spin_lock_irqsave(&dev->vblank_time_lock, flags); -- 2.30.2