[PATCH AUTOSEL 4.20 183/304] mmc: bcm2835: reset host on timeout

[Sasha Levin]

From: Michal Suchanek <msuchanek@xxxxxxx>

[ Upstream commit f6000a4eb34e6462bc0dd39809c1bb99f9633269 ]

The bcm2835 mmc host tends to lock up for unknown reason so reset it on
timeout. The upper mmc block layer tries retransimitting with single
blocks which tends to work out after a long wait.

This is better than giving up and leaving the machine broken for no
obvious reason.

Fixes: 660fc733bd74 ("mmc: bcm2835: Add new driver for the sdhost controller.")
Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
Acked-by: Eric Anholt <eric@xxxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/mmc/host/bcm2835.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
index aef40e1739ee..a251be266ad7 100644
--- a/drivers/mmc/host/bcm2835.c
+++ b/drivers/mmc/host/bcm2835.c
@@ -286,6 +286,7 @@ static void bcm2835_reset(struct mmc_host *mmc)
 
 	if (host->dma_chan)
 		dmaengine_terminate_sync(host->dma_chan);
+	host->dma_chan = NULL;
 	bcm2835_reset_internal(host);
 }
 
@@ -846,6 +847,8 @@ static void bcm2835_timeout(struct work_struct *work)
 		dev_err(dev, "timeout waiting for hardware interrupt.\n");
 		bcm2835_dumpregs(host);
 
+		bcm2835_reset(host->mmc);
+
 		if (host->data) {
 			host->data->error = -ETIMEDOUT;
 			bcm2835_finish_data(host);
-- 
2.19.1