mmc: dw_mmc: Do not wait for DTO in case of error

When running the ARTPEC-8 DWMMC IP version, and a data error interrupt
comes during a data read transfer, there is no guarantee for the data
transfer over interrupt (DTO) to come within the specified data timeout.
This case is handled by the dto_timer handler which will complete the
request with the comment:

 /*
  * If DTO interrupt does NOT come in sending data state,
  * we should notify the driver to terminate current transfer
  * and report a data timeout to the core.
  */

But since the ARTPEC-8 DWMMC IP version, supports an extended TMOUT
register which allows longer timeouts than the non ARTPEC-8 version
does, waiting for the dto_timer to complete the request in error cases
may cause the request to take significantly longer time than necessary.
This is specifically true for the failing steps during tuning of a
device.

Fix this by completing the request when the error interrupt comes. Since
this fix is specific for the ARTPEC-8, a quirk is added.

Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com>
Link: https://lore.kernel.org/r/20211220113026.21129-5-marten.lindahl@axis.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
index 3914024cf415..ca5be4445ae0 100644
--- a/drivers/mmc/host/dw_mmc-exynos.c
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -127,6 +127,11 @@ static int dw_mci_exynos_priv_init(struct dw_mci *host)
 				DQS_CTRL_GET_RD_DELAY(priv->saved_strobe_ctrl);
 	}
 
+	if (priv->ctrl_type == DW_MCI_TYPE_ARTPEC8) {
+		/* Quirk needed for the ARTPEC-8 SoC */
+		host->quirks |= DW_MMC_QUIRK_EXTENDED_TMOUT;
+	}
+
 	host->bus_hz /= (priv->ciu_div + 1);
 
 	return 0;