drm: Correct unbalanced drm_vblank_put() during mode setting.
The first time we install a mode, the vblank will be disabled for a pipe
and so drm_vblank_get() in drm_vblank_pre_modeset() will fail. As we
unconditionally call drm_vblank_put() afterwards, the vblank reference
counter becomes unbalanced.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 3795dbc..93e677a 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -435,6 +435,8 @@
*/
void drm_vblank_put(struct drm_device *dev, int crtc)
{
+ BUG_ON (atomic_read (&dev->vblank_refcount[crtc]) == 0);
+
/* Last user schedules interrupt disable */
if (atomic_dec_and_test(&dev->vblank_refcount[crtc]))
mod_timer(&dev->vblank_disable_timer, jiffies + 5*DRM_HZ);
@@ -460,8 +462,9 @@
* so that interrupts remain enabled in the interim.
*/
if (!dev->vblank_inmodeset[crtc]) {
- dev->vblank_inmodeset[crtc] = 1;
- drm_vblank_get(dev, crtc);
+ dev->vblank_inmodeset[crtc] = 0x1;
+ if (drm_vblank_get(dev, crtc) == 0)
+ dev->vblank_inmodeset[crtc] |= 0x2;
}
}
EXPORT_SYMBOL(drm_vblank_pre_modeset);
@@ -473,9 +476,12 @@
if (dev->vblank_inmodeset[crtc]) {
spin_lock_irqsave(&dev->vbl_lock, irqflags);
dev->vblank_disable_allowed = 1;
- dev->vblank_inmodeset[crtc] = 0;
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
- drm_vblank_put(dev, crtc);
+
+ if (dev->vblank_inmodeset[crtc] & 0x2)
+ drm_vblank_put(dev, crtc);
+
+ dev->vblank_inmodeset[crtc] = 0;
}
}
EXPORT_SYMBOL(drm_vblank_post_modeset);