2018-05-03 11:17:04

by Asutosh Das (asd)

[permalink] [raw]
Subject: [PATCH v2 01/10] scsi: ufs: Allowing power mode change

From: Yaniv Gardi <[email protected]>

Due to M-PHY issues, moving from HS to any other mode or gear or
even Hibern8 may cause some un-predicted behavior
of the device.
This patch adds provides a quirk to address that.

Signed-off-by: Yaniv Gardi <[email protected]>
Signed-off-by: Subhash Jadavani <[email protected]>
Signed-off-by: Can Guo <[email protected]>
Signed-off-by: Asutosh Das <[email protected]>
---
drivers/scsi/ufs/ufshcd.c | 8 +++++++-
drivers/scsi/ufs/ufshcd.h | 7 +++++++
2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 5bc9dc1..f3083fe 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4162,9 +4162,15 @@ static int ufshcd_link_startup(struct ufs_hba *hba)
goto out;
} while (ret && retries--);

- if (ret)
+ if (ret) {
/* failed to get the link up... retire */
goto out;
+ }
+
+ if (hba->quirks & UFSHCD_QUIRK_BROKEN_PWR_MODE_CHANGE) {
+ ufshcd_dme_set(hba, UIC_ARG_MIB(TX_LCC_ENABLE), 0);
+ ufshcd_dme_set(hba, UIC_ARG_MIB(TX_LCC_ENABLE), 1);
+ }

if (link_startup_again) {
link_startup_again = false;
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index cbe46f6..bb4ecfb 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -591,6 +591,13 @@ struct ufs_hba {
*/
#define UFSHCD_QUIRK_PRDT_BYTE_GRAN UFS_BIT(7)

+ /*
+ * Needs to be enabled if moving from HS to any other gear/mode or even
+ * hibern8 causes unpredicted behavior of device.
+ * If this quirk is enabled, standard UFS driver will disable/enable
+ * TX_LCC.
+ */
+ #define UFSHCD_QUIRK_BROKEN_PWR_MODE_CHANGE UFS_BIT(8)
unsigned int quirks; /* Deviations from standard UFSHCI spec. */

/* Device deviations from standard UFS device spec. */
--
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.



2018-05-16 21:10:39

by Subhash Jadavani

[permalink] [raw]
Subject: Re: [PATCH v2 01/10] scsi: ufs: Allowing power mode change

On 2018-05-03 04:07, Asutosh Das wrote:
> From: Yaniv Gardi <[email protected]>
>
> Due to M-PHY issues, moving from HS to any other mode or gear or
> even Hibern8 may cause some un-predicted behavior
> of the device.
> This patch adds provides a quirk to address that.
>
> Signed-off-by: Yaniv Gardi <[email protected]>
> Signed-off-by: Subhash Jadavani <[email protected]>
> Signed-off-by: Can Guo <[email protected]>
> Signed-off-by: Asutosh Das <[email protected]>
> ---
> drivers/scsi/ufs/ufshcd.c | 8 +++++++-
> drivers/scsi/ufs/ufshcd.h | 7 +++++++
> 2 files changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 5bc9dc1..f3083fe 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -4162,9 +4162,15 @@ static int ufshcd_link_startup(struct ufs_hba
> *hba)
> goto out;
> } while (ret && retries--);
>
> - if (ret)
> + if (ret) {
> /* failed to get the link up... retire */
> goto out;
> + }
> +
> + if (hba->quirks & UFSHCD_QUIRK_BROKEN_PWR_MODE_CHANGE) {
> + ufshcd_dme_set(hba, UIC_ARG_MIB(TX_LCC_ENABLE), 0);
> + ufshcd_dme_set(hba, UIC_ARG_MIB(TX_LCC_ENABLE), 1);
> + }
>
> if (link_startup_again) {
> link_startup_again = false;
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index cbe46f6..bb4ecfb 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -591,6 +591,13 @@ struct ufs_hba {
> */
> #define UFSHCD_QUIRK_PRDT_BYTE_GRAN UFS_BIT(7)
>
> + /*
> + * Needs to be enabled if moving from HS to any other gear/mode or
> even
> + * hibern8 causes unpredicted behavior of device.
> + * If this quirk is enabled, standard UFS driver will disable/enable
> + * TX_LCC.
> + */
> + #define UFSHCD_QUIRK_BROKEN_PWR_MODE_CHANGE UFS_BIT(8)
> unsigned int quirks; /* Deviations from standard UFSHCI spec. */
>
> /* Device deviations from standard UFS device spec. */

This was probably needed in early generation of UFS devices (non
commercial) and may not be really needed now. I believe we can skip this
patch.

--
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project