Re: [PATCH V2] mmc: core: improve reasonableness of bus width setting for HS400es
From: Ulf Hansson
Date: Mon Jul 16 2018 - 06:12:45 EST
On 11 July 2018 at 05:00, Hongjie Fang <hongjiefang@xxxxxxxxxxxx> wrote:
> mmc_select_hs400es() calls mmc_select_bus_width() which will continue
> to set 4bit transfer mode if fail to set 8bit mode. The bus width
> should not be set to 4bit in HS400es.
>
> When fail to set 8bit mode, need return error directly for HS400es.
>
> Signed-off-by: Hongjie Fang <hongjiefang@xxxxxxxxxxxx>
> ---
> drivers/mmc/core/mmc.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 4466f5d..4bd6c09 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -1021,8 +1021,11 @@ static int mmc_select_bus_width(struct mmc_card *card)
> EXT_CSD_BUS_WIDTH,
> ext_csd_bits[idx],
> card->ext_csd.generic_cmd6_time);
> - if (err)
> + if (err) {
> + if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400ES)
> + return err;
> continue;
> + }
I would rather let mmc_select_hs400es() check the return code from
mmc_select_bus_width().
So, if the return code isn't MMC_BUS_WIDTH_8, mmc_select_hs400es()
should bail out.
[...]
Kind regards
Uffe