Re: [PATCH v2] mmc: limit the time of retries when analyse tuples failed

[fengnan chang <fengnanchang@gmail.com>]

yeah, I think it should tag this for stable kernels as well.
I will send a new version later.

Ulf Hansson <ulf.hansson@linaro.org> 于2021年1月20日周三 下午11:29写道：
>
> On Wed, 20 Jan 2021 at 15:47, Fengnan Chang <fengnanchang@gmail.com> wrote:
> >
> > when analyse tuples failed, may enter an endless loop，so limit the time of retries.
>
> Since this is fixing a real bug for you, it looks like we should tag
> this for stable kernels as well, right?
>
> >
> > Signed-off-by: Fengnan Chang <fengnanchang@gmail.com>
> > ---
> >  drivers/mmc/core/sdio_cis.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/mmc/core/sdio_cis.c b/drivers/mmc/core/sdio_cis.c
> > index dcb3dee59fa5..47423a6d13fb 100644
> > --- a/drivers/mmc/core/sdio_cis.c
> > +++ b/drivers/mmc/core/sdio_cis.c
> > @@ -266,6 +266,7 @@ static int sdio_read_cis(struct mmc_card *card, struct sdio_func *func)
> >
> >         do {
> >                 unsigned char tpl_code, tpl_link;
> > +               u64 timeout = get_jiffies_64() + 10 * HZ;
>
> To be consistent with how we do time based polling (see
> __mmc_poll_for_busy() in mmc_ops.c for example) I would prefer if you
> use a define for the timeout, rather than a magic value as here.
>
> #define SDIO_READ_CIS_TIMEOUT_MS  (10 * 1000) /* 10s */
>
> Additionally, regular jiffies should be sufficient I think. Thus I
> prefer if you could specify the timeout along the lines like the
> below:
> timeout = jiffies + msecs_to_jiffies(SDIO_READ_CIS_TIMEOUT_MS);
>
> >
> >                 ret = mmc_io_rw_direct(card, 0, 0, ptr++, 0, &tpl_code);
> >                 if (ret)
> > @@ -318,6 +319,8 @@ static int sdio_read_cis(struct mmc_card *card, struct sdio_func *func)
> >                         prev = &this->next;
> >
> >                         if (ret == -ENOENT) {
> > +                               if (time_after64(get_jiffies_64(), timeout))
> > +                                       break;
> >                                 /* warn about unknown tuples */
> >                                 pr_warn_ratelimited("%s: queuing unknown"
> >                                        " CIS tuple 0x%02x (%u bytes)\n",
> > --
> > 2.25.1
> >
>
> Other than that, this looks okay to me.
>
> Kind regards
> Uffe