From 38e5597a03d2d1499a785230031c4f48e1d9c6b7 Mon Sep 17 00:00:00 2001 From: Archit Taneja Date: Fri, 11 Apr 2014 12:53:35 +0530 Subject: [PATCH] drm/omap: protect omap_crtc's event with event_lock spinlock The vblank_cb callback and the page_flip ioctl can occur together in different CPU contexts. vblank_cb uses takes tje drm device's event_lock spinlock when sending the vblank event and updating omap_crtc->event and omap_crtc->od_fb. Use the same spinlock in page_flip, to make sure the above omap_crtc parameters are configured sequentially. Signed-off-by: Archit Taneja Signed-off-by: Tomi Valkeinen --- drivers/gpu/drm/omapdrm/omap_crtc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c index 00798247190b..e3c47a8005ff 100644 --- a/drivers/gpu/drm/omapdrm/omap_crtc.c +++ b/drivers/gpu/drm/omapdrm/omap_crtc.c @@ -350,11 +350,15 @@ static int omap_crtc_page_flip_locked(struct drm_crtc *crtc, struct omap_crtc *omap_crtc = to_omap_crtc(crtc); struct drm_plane *primary = crtc->primary; struct drm_gem_object *bo; + unsigned long flags; DBG("%d -> %d (event=%p)", primary->fb ? primary->fb->base.id : -1, fb->base.id, event); + spin_lock_irqsave(&dev->event_lock, flags); + if (omap_crtc->old_fb) { + spin_unlock_irqrestore(&dev->event_lock, flags); dev_err(dev->dev, "already a pending flip\n"); return -EINVAL; } @@ -362,6 +366,8 @@ static int omap_crtc_page_flip_locked(struct drm_crtc *crtc, omap_crtc->event = event; omap_crtc->old_fb = primary->fb = fb; + spin_unlock_irqrestore(&dev->event_lock, flags); + /* * Hold a reference temporarily until the crtc is updated * and takes the reference to the bo. This avoids it -- 2.20.1