Commit 25f8203b authored by Vincent Whitchurch's avatar Vincent Whitchurch Committed by Ulf Hansson
Browse files

mmc: dw_mmc: Fix hang on data CRC error 



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: default avatarVincent Whitchurch <vincent.whitchurch@axis.com>
Reviewed-by: default avatarJaehoon 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: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent c500bee1

drivers/mmc/host/dw_mmc.c

+3 −3
Original line number Diff line number Diff line
@@ -2018,8 +2018,8 @@ static void dw_mci_tasklet_func(struct tasklet_struct *t) 
					continue;

				}



				dw_mci_stop_dma(host);

				send_stop_abort(host, data);

				dw_mci_stop_dma(host);

				state = STATE_SENDING_STOP;

				break;

			}
@@ -2043,10 +2043,10 @@ static void dw_mci_tasklet_func(struct tasklet_struct *t) 
			 */

			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;

			}
@@ -2079,10 +2079,10 @@ static void dw_mci_tasklet_func(struct tasklet_struct *t) 
			 */

			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;

			}