[PATCH 1/2] mmc: do not send cmd13 if the parameter 'send_status' is 0 for __mmc_switch
From: Haibo Chen haibo.chen@nxp.com
According to the code logic in __mmc_switch, if the parameter 'send_status' is zero, no need to send cmd13, just wait the stated timeout time, then can return directly.
Signed-off-by: Haibo Chen haibo.chen@nxp.com --- drivers/mmc/mmc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index d79cdef62e..6cb2af4232 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -805,8 +805,10 @@ static int __mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value, * capable of polling by using mmc_wait_dat0, then rely on waiting the * stated timeout to be sufficient. */ - if (ret == -ENOSYS && !send_status) + if (ret == -ENOSYS && !send_status) { mdelay(timeout_ms); + return 0; + }
/* Finally wait until the card is ready or indicates a failure * to switch. It doesn't hurt to use CMD13 here even if send_status
From: Haibo Chen haibo.chen@nxp.com
This 1ms delay before sending command already exist from the beginning of the fsl_esdhc driver added in year 2008. Now this driver has been split for two files: fsl_esdhc.c and fsl_esdhc_imx.c. fsl_esdhc_imx.c only for i.MX series. i.MX series esdhc/usdhc do not need this 1ms delay before sending any command. So remove this 1ms, this will save a lot time if handling a large mmc data.
Signed-off-by: Haibo Chen haibo.chen@nxp.com --- drivers/mmc/fsl_esdhc_imx.c | 7 ------- 1 file changed, 7 deletions(-)
diff --git a/drivers/mmc/fsl_esdhc_imx.c b/drivers/mmc/fsl_esdhc_imx.c index a0a0903ae4..ac65ed1ee1 100644 --- a/drivers/mmc/fsl_esdhc_imx.c +++ b/drivers/mmc/fsl_esdhc_imx.c @@ -462,13 +462,6 @@ static int esdhc_send_cmd_common(struct fsl_esdhc_priv *priv, struct mmc *mmc, while (esdhc_read32(®s->prsstat) & PRSSTAT_DLA) ;
- /* Wait at least 8 SD clock cycles before the next command */ - /* - * Note: This is way more than 8 cycles, but 1ms seems to - * resolve timing issues with some cards - */ - udelay(1000); - /* Set up for a data transfer if we have one */ if (data) { err = esdhc_setup_data(priv, mmc, data);
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