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* [PATCH v1] scsi: ufs-mediatek: Prevent LPM operation on undeclared VCC
@ 2020-07-24 14:16 Stanley Chu
  2020-07-27 10:56 ` Avri Altman
  2020-07-29  4:10 ` Martin K. Petersen
  0 siblings, 2 replies; 3+ messages in thread
From: Stanley Chu @ 2020-07-24 14:16 UTC (permalink / raw)
  To: linux-scsi, martin.petersen, avri.altman, alim.akhtar, jejb, bvanassche
  Cc: beanhuo, asutoshd, cang, matthias.bgg, linux-mediatek,
	linux-arm-kernel, linux-kernel, kuohong.wang, peter.wang,
	chun-hung.wu, andy.teng, chaotian.jing, cc.chou, Stanley Chu

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@mediatek.com>
---
 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)
 		return;
 
 	if (lpm & !hba->vreg_info.vcc->enabled)
-- 
2.18.0

^ permalink raw reply	[flat|nested] 3+ messages in thread

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2020-07-24 14:16 [PATCH v1] scsi: ufs-mediatek: Prevent LPM operation on undeclared VCC Stanley Chu
2020-07-27 10:56 ` Avri Altman
2020-07-29  4:10 ` Martin K. Petersen

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