From: Peter Wang peter.wang@mediatek.com
[ Upstream commit c625b80b9d00f3546722cd77527f9697c8c4c911 ]
As per spec, e.g. JESD220E chapter 7.2, while powering off the UFS device, RST_N signal should be between VSS(Ground) and VCCQ/VCCQ2. The power down sequence after fixing:
Power down:
1. Assert RST_N low
2. Turn-off VCC
3. Turn-off VCCQ/VCCQ2
Link: https://lore.kernel.org/r/1620813706-25331-1-git-send-email-peter.wang@media... Reviewed-by: Stanley Chu stanley.chu@mediatek.com Signed-off-by: Peter Wang peter.wang@mediatek.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/ufs/ufs-mediatek.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c index 09d2ac20508b..aace13399a7f 100644 --- a/drivers/scsi/ufs/ufs-mediatek.c +++ b/drivers/scsi/ufs/ufs-mediatek.c @@ -824,6 +824,7 @@ static void ufs_mtk_vreg_set_lpm(struct ufs_hba *hba, bool lpm) static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) { int err; + struct arm_smccc_res res;
if (ufshcd_is_link_hibern8(hba)) { err = ufs_mtk_link_set_lpm(hba); @@ -844,6 +845,9 @@ static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) ufs_mtk_vreg_set_lpm(hba, true); }
+ if (ufshcd_is_link_off(hba)) + ufs_mtk_device_reset_ctrl(0, res); + return 0; }