On Wed, 20 Jan 2021 at 15:47, Fengnan Chang <fengnanchang@xxxxxxxxx> 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@xxxxxxxxx>
> ---
> 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
