Re: [PATCH] mmc: core: Fix access to HS400-ES devices

[Guenter Roeck <linux@roeck-us.net>]

ping ...

Ulf,

I know it is early for a ping. However, the patch causing all HS400-ES
devices to fail already made it into various stable releases, and I think
it would be very desirable to get those back to working.

Thanks,
Guenter


On Wed, Mar 01, 2017 at 02:11:47PM -0800, Guenter Roeck wrote:
> HS400-ES devices fail to initialize with the following error messages.
> 
> mmc1: power class selection to bus width 8 ddr 0 failed
> mmc1: error -110 whilst initialising MMC card
> 
> This was seen on Samsung Chromebook Plus. Code analysis points to
> commit 3d4ef329757c ("mmc: core: fix multi-bit bus width without
> high-speed mode"), which attempts to set the bus width for all but
> HS200 devices unconditionally. However, for HS400-ES, the bus width
> is already selected.
> 
> Cc: Anssi Hannula <anssi.hannula@bitwise.fi>
> Cc: Douglas Anderson <dianders@chromium.org>
> Cc: Brian Norris <briannorris@chromium.org>
> Fixes: 3d4ef329757c ("mmc: core: fix multi-bit bus width ...")
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
>  drivers/mmc/core/mmc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 7fd722868875..b502601df228 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -1730,7 +1730,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>  		err = mmc_select_hs400(card);
>  		if (err)
>  			goto free_card;
> -	} else {
> +	} else if (!mmc_card_hs400es(card)) {
>  		/* Select the desired bus width optionally */
>  		err = mmc_select_bus_width(card);
>  		if (err > 0 && mmc_card_hs(card)) {
> -- 
> 2.7.4
>