Turning a CRTC off will prevent a queued page flip from ever completing,
potentially confusing userspace. Wait for queued page flips to complete
before turning the CRTC off to avoid this.
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Laurent Pinchart <[email protected]>
---
v2:
- Add Reviewed-by.
---
.../gpu/drm/renesas/shmobile/shmob_drm_crtc.c | 37 +++++++++++++++++++
.../gpu/drm/renesas/shmobile/shmob_drm_crtc.h | 3 ++
2 files changed, 40 insertions(+)
diff --git a/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c b/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c
index 0adf5d33ba31695e..20adb9d2fa178250 100644
--- a/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c
+++ b/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c
@@ -50,11 +50,40 @@ void shmob_drm_crtc_finish_page_flip(struct shmob_drm_crtc *scrtc)
scrtc->event = NULL;
if (event) {
drm_crtc_send_vblank_event(&scrtc->base, event);
+ wake_up(&scrtc->flip_wait);
drm_crtc_vblank_put(&scrtc->base);
}
spin_unlock_irqrestore(&dev->event_lock, flags);
}
+static bool shmob_drm_crtc_page_flip_pending(struct shmob_drm_crtc *scrtc)
+{
+ struct drm_device *dev = scrtc->base.dev;
+ unsigned long flags;
+ bool pending;
+
+ spin_lock_irqsave(&dev->event_lock, flags);
+ pending = scrtc->event != NULL;
+ spin_unlock_irqrestore(&dev->event_lock, flags);
+
+ return pending;
+}
+
+static void shmob_drm_crtc_wait_page_flip(struct shmob_drm_crtc *scrtc)
+{
+ struct drm_crtc *crtc = &scrtc->base;
+ struct shmob_drm_device *sdev = to_shmob_device(crtc->dev);
+
+ if (wait_event_timeout(scrtc->flip_wait,
+ !shmob_drm_crtc_page_flip_pending(scrtc),
+ msecs_to_jiffies(50)))
+ return;
+
+ dev_warn(sdev->dev, "page flip timeout\n");
+
+ shmob_drm_crtc_finish_page_flip(scrtc);
+}
+
/* -----------------------------------------------------------------------------
* CRTC
*/
@@ -253,6 +282,12 @@ static void shmob_drm_crtc_stop(struct shmob_drm_crtc *scrtc)
if (!scrtc->started)
return;
+ /*
+ * Wait for page flip completion before stopping the CRTC as userspace
+ * expects page flips to eventually complete.
+ */
+ shmob_drm_crtc_wait_page_flip(scrtc);
+
/* Stop the LCDC. */
shmob_drm_crtc_start_stop(scrtc, false);
@@ -463,6 +498,8 @@ int shmob_drm_crtc_create(struct shmob_drm_device *sdev)
unsigned int i;
int ret;
+ init_waitqueue_head(&sdev->crtc.flip_wait);
+
sdev->crtc.dpms = DRM_MODE_DPMS_OFF;
primary = shmob_drm_plane_create(sdev, DRM_PLANE_TYPE_PRIMARY, 0);
diff --git a/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.h b/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.h
index 2c6d7541427581a6..b9863e026e8a9b83 100644
--- a/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.h
+++ b/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.h
@@ -14,6 +14,8 @@
#include <drm/drm_connector.h>
#include <drm/drm_encoder.h>
+#include <linux/wait.h>
+
#include <video/videomode.h>
struct drm_pending_vblank_event;
@@ -24,6 +26,7 @@ struct shmob_drm_crtc {
struct drm_crtc base;
struct drm_pending_vblank_event *event;
+ wait_queue_head_t flip_wait;
int dpms;
const struct shmob_drm_format_info *format;
--
2.34.1