RE: [PATCH 6/8] scsi: ufs: Add dev ref clock gating wait time support

[Avri Altman]

> In UFS version 3.0, a newly added attribute bRefClkGatingWaitTime defines
> the minimum time for which the reference clock is required by device during
> transition to LS-MODE or HIBERN8 state. Make this change to reflect the new
> requirement by adding delays before turning off the clock.
> 
> Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
> Reviewed-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
> Reviewed-by: Bean Huo <beanhuo@xxxxxxxxxx>
> 
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index cfe3803..990cb48 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -167,6 +167,7 @@ enum attr_idn {
>         QUERY_ATTR_IDN_FFU_STATUS               = 0x14,
>         QUERY_ATTR_IDN_PSA_STATE                = 0x15,
>         QUERY_ATTR_IDN_PSA_DATA_SIZE            = 0x16,
> +       QUERY_ATTR_IDN_REF_CLK_GATING_WAIT_TIME = 0x17,
>  };
> 
>  /* Descriptor idn for Query requests */
> @@ -534,6 +535,8 @@ struct ufs_dev_info {
>         u16 wmanufacturerid;
>         /*UFS device Product Name */
>         u8 *model;
> +       u16 wspecversion;
> +       u32 clk_gating_wait_us;
>  };
> 
>  /**
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index e8f7f9d..76beaf9 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -91,6 +91,9 @@
>  /* default delay of autosuspend: 2000 ms */
>  #define RPM_AUTOSUSPEND_DELAY_MS 2000
> 
> +/* Default value of wait time before gating device ref clock */
> +#define UFSHCD_REF_CLK_GATING_WAIT_US 0xFF /* microsecs */
> +
>  #define ufshcd_toggle_vreg(_dev, _vreg, _on)                           \
>         ({                                                              \
>                 int _ret;                                               \
> @@ -3281,6 +3284,29 @@ static inline int
> ufshcd_read_unit_desc_param(struct ufs_hba *hba,
>                                       param_offset, param_read_buf, param_size);
>  }
> 
> +static int ufshcd_get_ref_clk_gating_wait(struct ufs_hba *hba)
> +{
> +       int err = 0;
> +       u32 gating_wait = UFSHCD_REF_CLK_GATING_WAIT_US;
> +
> +       if (hba->dev_info.wspecversion >= 0x300) {
> +               err = ufshcd_query_attr_retry(hba,
> UPIU_QUERY_OPCODE_READ_ATTR,
> +                               QUERY_ATTR_IDN_REF_CLK_GATING_WAIT_TIME, 0, 0,
> +                               &gating_wait);
> +               if (err)
> +                       dev_err(hba->dev, "Failed reading bRefClkGatingWait. err =
> %d, use default %uus\n",
> +                                        err, gating_wait);
> +
> +               if (gating_wait == 0) {
> +                       gating_wait = UFSHCD_REF_CLK_GATING_WAIT_US;
> +                       dev_err(hba->dev, "Undefined ref clk gating wait time, use
> default %uus\n",
> +                                        gating_wait);
> +               }

You forgot to set
hba->dev_info.clk_gating_wait_us = gating_wait

Thanks,
Avri