scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic
authorCan Guo <cang@codeaurora.org>
Tue, 11 Feb 2020 03:40:48 +0000 (19:40 -0800)
committerMartin K. Petersen <martin.petersen@oracle.com>
Thu, 13 Feb 2020 00:42:36 +0000 (19:42 -0500)
commitc63d6099a7959ecc919b2549dc6b71f53521f819
treed74b1e95f6b2352308da81421b213d13ce0d658a
parent38f3242e9e2022a7613dd4c108f2b7d55a9bb00a
scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic

The async version of ufshcd_hold(async == true), which is only called in
queuecommand path as for now, is expected to work in atomic context, thus
it should not sleep or schedule out. When it runs into the condition that
clocks are ON but link is still in hibern8 state, it should bail out
without flushing the clock ungate work.

Fixes: f2a785ac2312 ("scsi: ufshcd: Fix race between clk scaling and ungate work")
Link: https://lore.kernel.org/r/1581392451-28743-6-git-send-email-cang@codeaurora.org
Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
drivers/scsi/ufs/ufshcd.c