[PATCH 4.4 87/97] drm/omap: DMM: Check for DMM readiness after successful transaction commit

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Peter Ujfalusi <peter.ujfalusi@xxxxxx>


[ Upstream commit b7ea6b286c4051e043f691781785e3c4672f014a ]

Check the status of the DMM engine after it is reported that the
transaction was completed as in rare cases the engine might not reached a
working state.

The wait_status() will print information in case the DMM is not reached the
expected state and the dmm_txn_commit() will return with an error code to
make sure that we are not continuing with a broken setup.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/omapdrm/omap_dmm_tiler.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c
+++ b/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c
@@ -288,7 +288,12 @@ static int dmm_txn_commit(struct dmm_txn
 				msecs_to_jiffies(100))) {
 			dev_err(dmm->dev, "timed out waiting for done\n");
 			ret = -ETIMEDOUT;
+			goto cleanup;
 		}
+
+		/* Check the engine status before continue */
+		ret = wait_status(engine, DMM_PATSTATUS_READY |
+				  DMM_PATSTATUS_VALID | DMM_PATSTATUS_DONE);
 	}
 
 cleanup: