drm/exynos: fix pending update handling
Exynos DRM devices update their registers at vblank time. Exynos-DRM uses
custom mechanism to wait for vblank. This mechanism is error prone -
variables are not updated atomically. As a result in certain circumstances
user space can try to free buffers which are still in use by hardware,
in such cases IOMMU can throw OOPS.
The patch instead of fixing the mechanism replaces it with drm core helper.
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
diff --git a/drivers/gpu/drm/exynos/exynos_drm_crtc.c b/drivers/gpu/drm/exynos/exynos_drm_crtc.c
index 785ffa6..5b6845b 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_crtc.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_crtc.c
@@ -134,8 +134,6 @@
exynos_crtc->ops = ops;
exynos_crtc->ctx = ctx;
- init_waitqueue_head(&exynos_crtc->wait_update);
-
crtc = &exynos_crtc->base;
private->crtc[pipe] = crtc;
@@ -175,13 +173,6 @@
exynos_crtc->ops->disable_vblank(exynos_crtc);
}
-void exynos_drm_crtc_wait_pending_update(struct exynos_drm_crtc *exynos_crtc)
-{
- wait_event_timeout(exynos_crtc->wait_update,
- (atomic_read(&exynos_crtc->pending_update) == 0),
- msecs_to_jiffies(50));
-}
-
void exynos_drm_crtc_finish_update(struct exynos_drm_crtc *exynos_crtc,
struct exynos_drm_plane *exynos_plane)
{
@@ -190,9 +181,6 @@
exynos_plane->pending_fb = NULL;
- if (atomic_dec_and_test(&exynos_crtc->pending_update))
- wake_up(&exynos_crtc->wait_update);
-
spin_lock_irqsave(&crtc->dev->event_lock, flags);
if (exynos_crtc->event)
drm_crtc_send_vblank_event(crtc, exynos_crtc->event);
@@ -235,10 +223,8 @@
spin_lock_irqsave(&crtc->dev->event_lock, flags);
e = exynos_crtc->event;
- if (e && e->base.file_priv == file) {
+ if (e && e->base.file_priv == file)
exynos_crtc->event = NULL;
- atomic_dec(&exynos_crtc->pending_update);
- }
spin_unlock_irqrestore(&crtc->dev->event_lock, flags);