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mmc: core: Avoid hanging to claim host for mmc via some nested calls 

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: 81196976ed ("mmc: block: Add blk-mq support")
Reported-by: Dmitry Osipenko <digetx@gmail.com>
Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
This commit is contained in:
Ulf Hansson 2018-02-27 11:49:09 +01:00
parent 5b43df8b4c
commit 3a574919f0
1 changed files with 0 additions and 4 deletions
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4
drivers/mmc/core/mmc_ops.c
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@ -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;