From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Kurtz Subject: Re: [PATCH v2 02/18] drm/exynos: use wait_event_timeout() for safety usage Date: Wed, 21 May 2014 14:01:12 +0800 Message-ID: References: <1400647390-26590-1-git-send-email-yj44.cho@samsung.com> <1400647390-26590-3-git-send-email-yj44.cho@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1400647390-26590-3-git-send-email-yj44.cho@samsung.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: YoungJun Cho Cc: Mark Rutland , devicetree@vger.kernel.org, linux-samsung-soc , Pawel Moll , Ian Campbell , Seung-Woo Kim , dri-devel , Andrzej Hajda , Kyungmin Park , Rob Herring , Laurent Pinchart , Kumar Gala , Kukjin Kim , s.trumtrar@pengutronix.de List-Id: devicetree@vger.kernel.org On Wed, May 21, 2014 at 12:42 PM, YoungJun Cho wrote: > There could be the case that the page flip operation isn't finished correctly > with some abnormal condition such as panel reset. So this patch replaces > wait_event() with wait_event_timeout() to avoid waiting for page flip completion > infinitely. > And clears exynos_crtc->pending_flip in exynos_drm_crtc_page_flip() when > exynos_drm_crtc_mode_set_commit() is failed. > > Signed-off-by: YoungJun Cho > Acked-by: Inki Dae > Acked-by: Kyungmin Park > --- > drivers/gpu/drm/exynos/exynos_drm_crtc.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/exynos/exynos_drm_crtc.c b/drivers/gpu/drm/exynos/exynos_drm_crtc.c > index 95c9435..3bf091d 100644 > --- a/drivers/gpu/drm/exynos/exynos_drm_crtc.c > +++ b/drivers/gpu/drm/exynos/exynos_drm_crtc.c > @@ -69,8 +69,10 @@ static void exynos_drm_crtc_dpms(struct drm_crtc *crtc, int mode) > > if (mode > DRM_MODE_DPMS_ON) { > /* wait for the completion of page flip. */ > - wait_event(exynos_crtc->pending_flip_queue, > - atomic_read(&exynos_crtc->pending_flip) == 0); > + if (!wait_event_timeout(exynos_crtc->pending_flip_queue, > + !atomic_read(&exynos_crtc->pending_flip), > + HZ/20)) > + atomic_set(&exynos_crtc->pending_flip, 0); I meant that changing this to wait_event_timeout() seems to be masking the original problem, that pending_flip wasn't being cleared. Now that you are now clearing pending_flip in the error path, you don't need the timeout, right? -Dan > drm_vblank_off(crtc->dev, exynos_crtc->pipe); > } > > @@ -259,6 +261,7 @@ static int exynos_drm_crtc_page_flip(struct drm_crtc *crtc, > spin_lock_irq(&dev->event_lock); > drm_vblank_put(dev, exynos_crtc->pipe); > list_del(&event->base.link); > + atomic_set(&exynos_crtc->pending_flip, 0); > spin_unlock_irq(&dev->event_lock); > > goto out; > -- > 1.7.9.5 >