scsi: ufs: core: Narrow down fast path in system suspend path
authorCan Guo <cang@codeaurora.org>
Mon, 26 Apr 2021 03:48:40 +0000 (20:48 -0700)
committerMartin K. Petersen <martin.petersen@oracle.com>
Thu, 29 Apr 2021 03:15:18 +0000 (23:15 -0400)
commitce4f62f9dd8cf43ac044045ed598a0b80ef33890
tree523db6cfaa6cc77d8e91de675f68b2d853cb91bc
parent637822e63b79ee8a729f7ba2645a26cf5a524ee4
scsi: ufs: core: Narrow down fast path in system suspend path

If spm_lvl is set to 0 or 1, when system suspend kicks start and HBA is
runtime active, system suspend may just bail without doing anything (the
fast path), leaving other contexts still running, e.g., clock gating and
clock scaling. When system resume kicks start, concurrency can happen
between ufshcd_resume() and these contexts, leading to various stability
issues.

Add a check against HBA's runtime state and allowing fast path only if HBA
is runtime suspended, otherwise let system suspend go ahead call
ufshcd_suspend(). This will guarantee that these contexts are stopped by
either runtime suspend or system suspend.

Link: https://lore.kernel.org/r/1619408921-30426-4-git-send-email-cang@codeaurora.org
Fixes: 0b257734344a ("scsi: ufs: optimize system suspend handling")
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
drivers/scsi/ufs/ufshcd.c