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)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 24 Apr 2020 06:00:54 +0000 (08:00 +0200)
commit78ef0452f798f0c798e2db80da9adaa6d9f24edb
treeece7948db853c316bf58109b863050460869dd84
parente7358097b643b97651c98ff8d75366710aabcf19
scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic

commit c63d6099a7959ecc919b2549dc6b71f53521f819 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/scsi/ufs/ufshcd.c