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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Michal Suchanek <msuchanek@suse.de>,
        Stefan Wahren <stefan.wahren@i2se.com>,
        Eric Anholt <eric@anholt.net>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.20 172/352] mmc: bcm2835: reset host on timeout
Date:   Mon, 11 Feb 2019 15:16:39 +0100
Message-Id: <20190211141858.031888480@linuxfoundation.org>
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4.20-stable review patch.  If anyone has any objections, please let me know.

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

[ 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@suse.de>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 abf1f3c8b0c3..5301302fb531 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