Performing MMC block IO with simultaneous STR can lead to a deadlock: the mmc_pm_notify() function claims the host and then calls bus .remove() method, which lands in mmc_blk_remove(), which calls mmc_blk_remove_req() then it goes to -> mmc_cleanup_queue() -> kthread_stop(), which waits for the mmc-block thread to stop. If the mmc-block thread at that time is processing block requests, it will also try to claim the host in mmc_blk_issue_rq() and block there. This patch fixes the problem by calling .remove() before claiming the host.
Signed-off-by: Guennadi Liakhovetski <[email protected]> --- drivers/mmc/core/core.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index a2aa860..a68f085 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -2476,11 +2476,11 @@ int mmc_pm_notify(struct notifier_block *notify_block, if (!host->bus_ops || host->bus_ops->suspend) break; - mmc_claim_host(host); - + /* On 2 occasions above bus_ops->remove() is called unlocked */ if (host->bus_ops->remove) host->bus_ops->remove(host); + mmc_claim_host(host); mmc_detach_bus(host); mmc_power_off(host); mmc_release_host(host); -- 1.7.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
