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

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Message-ID: <20180308045810.8041-177-alexander.levin@microsoft.com>
Date:   Thu, 8 Mar 2018 05:00:10 +0000
From:   Sasha Levin <Alexander.Levin@...rosoft.com>
To:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>
CC:     Peter Ujfalusi <peter.ujfalusi@...com>,
        Tomi Valkeinen <tomi.valkeinen@...com>,
        Sasha Levin <Alexander.Levin@...rosoft.com>
Subject: [PATCH AUTOSEL for 4.9 177/190] drm/omap: DMM: Check for DMM
 readiness after successful transaction commit

From: Peter Ujfalusi <peter.ujfalusi@...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.ujfalusi@...com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@...com>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.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