[PATCH AUTOSEL for 3.18 51/53] drm/omap: DMM: Check for DMM readiness after successful transaction commit

From: Sasha Levin
Date: Thu Mar 08 2018 - 00:12:12 EST


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>
---
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 56c60552abba..f732d4ce7e4f 100644
--- a/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c
+++ b/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c
@@ -280,7 +280,12 @@ static int dmm_txn_commit(struct dmm_txn *txn, bool wait)
msecs_to_jiffies(1)) <= 0) {
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