RE: [PATCH V3] mmc: core: improve reasonableness of bus width setting for HS400es

[Fang Hongjie(æææ)]

> On 16 July 2018 at 13:11, 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..b2e1eb6 100644
> > --- a/drivers/mmc/core/mmc.c
> > +++ b/drivers/mmc/core/mmc.c
> > @@ -1338,8 +1338,11 @@ static int mmc_select_hs400es(struct mmc_card *card)
> >                 goto out_err;
> >
> >         err = mmc_select_bus_width(card);
> > -       if (err < 0)
> > +       if (err != MMC_BUS_WIDTH_8) {
> > +               pr_err("%s: switch to 8bit bus width failed, err:%d\n",
> > +                       mmc_hostname(host), err);
> >                 goto out_err;
> 
> You need to set err to a proper error code, else you may return a
> non-error code from the out_err label.

How about using the EIO or ENOTSUPP?

> 
> [...]
> 
> Kind regards
> Uffe

B&R
Hongjie