[PATCH AUTOSEL for 4.9 177/190] drm/omap: DMM: Check for DMM readiness after successful transaction commit

[Sasha Levin]

From: Peter Ujfalusi <peter.ujfal...@ti.com>

[ 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.ujfal...@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkei...@ti.com>
Signed-off-by: Sasha Levin <alexander.le...@microsoft.com>
---
 drivers/gpu/drm/omapdrm/omap_dmm_tiler.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c 
b/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c
index 4b83e9eeab06..7def04049498 100644
--- a/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c
+++ b/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c
@@ -298,7 +298,12 @@ static int dmm_txn_commit(struct dmm_txn *txn, bool wait)
                                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:
-- 
2.14.1