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 <archit at ti.com>
---
 drivers/gpu/drm/omapdrm/omap_crtc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c 
b/drivers/gpu/drm/omapdrm/omap_crtc.c
index d74c72c..9c7af42 100644
--- a/drivers/gpu/drm/omapdrm/omap_crtc.c
+++ b/drivers/gpu/drm/omapdrm/omap_crtc.c
@@ -350,6 +350,7 @@ static int omap_crtc_page_flip_locked(struct drm_crtc *crtc,
        struct drm_device *dev = crtc->dev;
        struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
        struct drm_gem_object *bo;
+       unsigned long flags;

        DBG("%d -> %d (event=%p)", crtc->fb ? crtc->fb->base.id : -1,
                        fb->base.id, event);
@@ -359,9 +360,12 @@ static int omap_crtc_page_flip_locked(struct drm_crtc 
*crtc,
                return -EINVAL;
        }

+       spin_lock_irqsave(&dev->event_lock, flags);
+
        omap_crtc->event = event;
        omap_crtc->old_fb = crtc->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
-- 
1.8.3.2

Reply via email to