diff mbox series

[v1,1/1] scsi: ufs-mediatek: fix ufs power down specs violation

Message ID 1620808746-21082-2-git-send-email-peter.wang@mediatek.com (mailing list archive)
State Superseded
Headers show
Series [v1,1/1] scsi: ufs-mediatek: fix ufs power down specs violation | expand

Commit Message

Peter Wang (王信友) May 12, 2021, 8:39 a.m. UTC
From: Peter Wang <peter.wang@mediatek.com>

As per specs, 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 as below:

Power down:
1. Assert RST_N low
2. Turn-off VCC
3. Turn-off VCCQ/VCCQ2

Change-Id: I297e9afe3c22bb1a5fc5e7acce9b5ecfd20181ed
Signed-off-by: Peter Wang <peter.wang@mediatek.com>
---
 drivers/scsi/ufs/ufs-mediatek.c |    4 ++++
 1 file changed, 4 insertions(+)

Comments

Stanley Chu May 12, 2021, 8:57 a.m. UTC | #1
Hi Peter,

Thanks for posting this fix.

On Wed, 2021-05-12 at 16:39 +0800, peter.wang@mediatek.com wrote:
> From: Peter Wang <peter.wang@mediatek.com>
> 
> As per specs, 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 as below:
> 
> Power down:
> 1. Assert RST_N low
> 2. Turn-off VCC
> 3. Turn-off VCCQ/VCCQ2
> 
> Change-Id: I297e9afe3c22bb1a5fc5e7acce9b5ecfd20181ed

Please drop Change-Id line.

> Signed-off-by: Peter Wang <peter.wang@mediatek.com>
> ---
>  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 c55202b..47b4066 100644
> --- a/drivers/scsi/ufs/ufs-mediatek.c
> +++ b/drivers/scsi/ufs/ufs-mediatek.c
> @@ -922,6 +922,7 @@ 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);
> @@ -941,6 +942,9 @@ static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  			goto fail;
>  	}
>  
> +	if (ufshcd_is_link_off(hba))
> +		ufs_mtk_device_reset_ctrl(0, res);
> +

Please also consider the case: Linkoff during suspend. In this case, HW
reset pin shall be released during resume flow.

Thanks,
Stanley Chu
diff mbox series

Patch

diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index c55202b..47b4066 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -922,6 +922,7 @@  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);
@@ -941,6 +942,9 @@  static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 			goto fail;
 	}
 
+	if (ufshcd_is_link_off(hba))
+		ufs_mtk_device_reset_ctrl(0, res);
+
 	return 0;
 fail:
 	/*