On 27/02/18 13:22, Ulf Hansson wrote:
> As the block layer, since the conversion to blkmq, claims the host using a
> context, a following nested call to mmc_claim_host(), which isn't using a
> context, may hang.
>
> Calling mmc_interrupt_hpi() and mmc_read_bkops_status() via the mmc block
> layer, may suffer from this problem, as these functions are calling
> mmc_claim|release_host().
>
> Let's fix the problem by removing the calls to mmc_claim|release_host()
> from the above mentioned functions and instead make the callers responsible
> of claiming/releasing the host. As a matter of fact, the existing callers
> already deals with it.
>
> Fixes: 81196976ed94 ("mmc: block: Add blk-mq support")
> Reported-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> Suggested-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Tested-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/mmc/core/mmc_ops.c | 4 ----
> 1 file changed, 4 deletions(-)
>
> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
> index 908e4db..42d6aa8 100644
> --- a/drivers/mmc/core/mmc_ops.c
> +++ b/drivers/mmc/core/mmc_ops.c
> @@ -848,7 +848,6 @@ int mmc_interrupt_hpi(struct mmc_card *card)
> return 1;
> }
>
> - mmc_claim_host(card->host);
> err = mmc_send_status(card, &status);
> if (err) {
> pr_err("%s: Get card status fail\n", mmc_hostname(card->host));
> @@ -890,7 +889,6 @@ int mmc_interrupt_hpi(struct mmc_card *card)
> } while (!err);
>
> out:
> - mmc_release_host(card->host);
> return err;
> }
>
> @@ -932,9 +930,7 @@ static int mmc_read_bkops_status(struct mmc_card *card)
> int err;
> u8 *ext_csd;
>
> - mmc_claim_host(card->host);
> err = mmc_get_ext_csd(card, &ext_csd);
> - mmc_release_host(card->host);
> if (err)
> return err;
>
>
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