[PATCH] mmc: sdhci-esdhc-imx: increase the pad I/O drive strength for DDR50 card

[PATCH] mmc: sdhci-esdhc-imx: increase the pad I/O drive strength for DDR50 card

[Haibo Chen]

Currently for DDR50 card, it need tuning in default. We meet tuning fail
issue for DDR50 card and some data CRC error when DDR50 sd card works.

This is because the default pad I/O drive strength can't make sure DDR50
card work stable. So increase the pad I/O drive strength for DDR50 card,
and use pins_100mhz.

Tested-and-reported-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Cc: stable@vger.kernel.org # v4.4+
---
 drivers/mmc/host/sdhci-esdhc-imx.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index cf666a0..abad67a 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -830,6 +830,7 @@ static int esdhc_change_pinstate(struct sdhci_host *host,
 
 	switch (uhs) {
 	case MMC_TIMING_UHS_SDR50:
+	case MMC_TIMING_UHS_DDR50:
 		pinctrl = imx_data->pins_100mhz;
 		break;
 	case MMC_TIMING_UHS_SDR104:
-- 
1.9.1

Re: [PATCH] mmc: sdhci-esdhc-imx: increase the pad I/O drive strength for DDR50 card

[Adrian Hunter]

On 17/04/17 14:10, Haibo Chen wrote:
> Currently for DDR50 card, it need tuning in default. We meet tuning fail
> issue for DDR50 card and some data CRC error when DDR50 sd card works.
> 
> This is because the default pad I/O drive strength can't make sure DDR50
> card work stable. So increase the pad I/O drive strength for DDR50 card,
> and use pins_100mhz.
> 
> Tested-and-reported-by: Tim Harvey <tharvey@gateworks.com>
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
> Cc: stable@vger.kernel.org # v4.4+

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>  drivers/mmc/host/sdhci-esdhc-imx.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index cf666a0..abad67a 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -830,6 +830,7 @@ static int esdhc_change_pinstate(struct sdhci_host *host,
>  
>  	switch (uhs) {
>  	case MMC_TIMING_UHS_SDR50:
> +	case MMC_TIMING_UHS_DDR50:
>  		pinctrl = imx_data->pins_100mhz;
>  		break;
>  	case MMC_TIMING_UHS_SDR104:
> 

Re: [PATCH] mmc: sdhci-esdhc-imx: increase the pad I/O drive strength for DDR50 card

[Dong Aisheng]

On Mon, Apr 17, 2017 at 07:10:02PM +0800, Haibo Chen wrote:
> Currently for DDR50 card, it need tuning in default. We meet tuning fail
> issue for DDR50 card and some data CRC error when DDR50 sd card works.
> 
> This is because the default pad I/O drive strength can't make sure DDR50
> card work stable. So increase the pad I/O drive strength for DDR50 card,
> and use pins_100mhz.
> 
> Tested-and-reported-by: Tim Harvey <tharvey@gateworks.com>
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
> Cc: stable@vger.kernel.org # v4.4+

Acked-by: Dong Aisheng <aisheng.dong@nxp.com>

Regards
Dong Aisheng

Re: [PATCH] mmc: sdhci-esdhc-imx: increase the pad I/O drive strength for DDR50 card

[Tim Harvey]

On Mon, Apr 17, 2017 at 4:10 AM, Haibo Chen <haibo.chen@nxp.com> wrote:
> Currently for DDR50 card, it need tuning in default. We meet tuning fail
> issue for DDR50 card and some data CRC error when DDR50 sd card works.
>
> This is because the default pad I/O drive strength can't make sure DDR50
> card work stable. So increase the pad I/O drive strength for DDR50 card,
> and use pins_100mhz.
>
> Tested-and-reported-by: Tim Harvey <tharvey@gateworks.com>
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
> Cc: stable@vger.kernel.org # v4.4+

Haibo,

I believe for stable to know how far back this needs to be applied (to
4.4) you need to add something like the following in your commit log:

This fixes DDR50 card support for IMX since DDR50 tuning was enabled
from commit 9faac7b95ea4 (mmc: sdhci: enable tuning for DDR50)

Regards,

Tim