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mmc: dw_mmc: Fix hang on data CRC error
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[ Upstream commit 25f8203 ]

When a Data CRC interrupt is received, the driver disables the DMA, then
sends the stop/abort command and then waits for Data Transfer Over.

However, sometimes, when a data CRC error is received in the middle of a
multi-block write transfer, the Data Transfer Over interrupt is never
received, and the driver hangs and never completes the request.

The driver sets the BMOD.SWR bit (SDMMC_IDMAC_SWRESET) when stopping the
DMA, but according to the manual CMD.STOP_ABORT_CMD should be programmed
"before assertion of SWR".  Do these operations in the recommended
order.  With this change the Data Transfer Over is always received
correctly in my tests.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210630102232.16011-1-vincent.whitchurch@axis.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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vwax authored and Sasha Levin committed Aug 26, 2021
1 parent 645fd92 commit f8dac27
Showing 1 changed file with 3 additions and 3 deletions.
6 changes: 3 additions & 3 deletions drivers/mmc/host/dw_mmc.c
Expand Up @@ -2018,8 +2018,8 @@ static void dw_mci_tasklet_func(unsigned long priv)
continue;
}

dw_mci_stop_dma(host);
send_stop_abort(host, data);
dw_mci_stop_dma(host);
state = STATE_SENDING_STOP;
break;
}
Expand All @@ -2043,10 +2043,10 @@ static void dw_mci_tasklet_func(unsigned long priv)
*/
if (test_and_clear_bit(EVENT_DATA_ERROR,
&host->pending_events)) {
dw_mci_stop_dma(host);
if (!(host->data_status & (SDMMC_INT_DRTO |
SDMMC_INT_EBE)))
send_stop_abort(host, data);
dw_mci_stop_dma(host);
state = STATE_DATA_ERROR;
break;
}
Expand Down Expand Up @@ -2079,10 +2079,10 @@ static void dw_mci_tasklet_func(unsigned long priv)
*/
if (test_and_clear_bit(EVENT_DATA_ERROR,
&host->pending_events)) {
dw_mci_stop_dma(host);
if (!(host->data_status & (SDMMC_INT_DRTO |
SDMMC_INT_EBE)))
send_stop_abort(host, data);
dw_mci_stop_dma(host);
state = STATE_DATA_ERROR;
break;
}
Expand Down

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