On 2/18/19 5:16 AM, chee.hong.ang@intel.com wrote:
From: "Ang, Chee Hong" chee.hong.ang@intel.com
'SET_BLOCKLEN' may occasionally fail on first attempt.
Why ?
This patch enable a small delay in dwmci_send_cmd() on busy, I/O or CRC error to allow the MMC controller recovers from the failure/error on subsequent retries.
Why 100 uS ?
Can we rather detect whether the controller recovered by polling some bit?
Signed-off-by: Ang, Chee Hong chee.hong.ang@intel.com
drivers/mmc/dw_mmc.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c index 7544b84..8dcc518 100644 --- a/drivers/mmc/dw_mmc.c +++ b/drivers/mmc/dw_mmc.c @@ -266,8 +266,11 @@ static int dwmci_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, if (data) flags = dwmci_set_transfer_mode(host, data);
- if ((cmd->resp_type & MMC_RSP_136) && (cmd->resp_type & MMC_RSP_BUSY))
return -1;
if ((cmd->resp_type & MMC_RSP_136) &&
(cmd->resp_type & MMC_RSP_BUSY)) {ret = -1;goto delay_ret;}
if (cmd->cmdidx == MMC_CMD_STOP_TRANSMISSION) flags |= DWMCI_CMD_ABORT_STOP;
@@ -316,11 +319,13 @@ static int dwmci_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, return -ETIMEDOUT; } else if (mask & DWMCI_INTMSK_RE) { debug("%s: Response Error.\n", __func__);
return -EIO;
ret = -EIO;goto delay_ret;
return -EIO;
ret = -EIO;goto delay_ret;@@ -347,6 +352,7 @@ static int dwmci_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, } }
+delay_ret: udelay(100);
return ret;