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

From: Ulf Hansson
Date: Tue Mar 14 2017 - 12:22:15 EST


On 1 March 2017 at 23:11, Guenter Roeck <linux@xxxxxxxxxxxx> 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@xxxxxxxxxx>
> Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Cc: Brian Norris <briannorris@xxxxxxxxxxxx>
> Fixes: 3d4ef329757c ("mmc: core: fix multi-bit bus width ...")
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Sorry for the delay. Been traveling.

Applied for fixes, thanks!

Kind regards
Uffe

> ---
> 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
>