On 2018/2/27 19:22, 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.
Reviewed-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
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>
---
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;
--
Best Regards
Shawn Lin
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