[PATCH v1] scsi: ufs-mediatek: Prevent LPM operation on undeclared VCC

From: Stanley Chu
Date: Fri Jul 24 2020 - 10:16:35 EST

In some platforms, VCC regulator may not be declared in device tree
to keep itself "always-on". In this case, hba->vreg_info.vcc is NULL
and shall not be operated during any flow.

Prevent possible NULL hba->vreg_info.vcc access in LPM mode by checking
if it is valid first.

Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
drivers/scsi/ufs/ufs-mediatek.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index 31af8b3d2b53..66223fe200fc 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -574,7 +574,7 @@ static int ufs_mtk_link_set_lpm(struct ufs_hba *hba)

static void ufs_mtk_vreg_set_lpm(struct ufs_hba *hba, bool lpm)
- if (!hba->vreg_info.vccq2)
+ if (!hba->vreg_info.vccq2 || !hba->vreg_info.vcc)

if (lpm & !hba->vreg_info.vcc->enabled)