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

[Can Guo <cang@xxxxxxxxxxxxxx>]

On 2020-02-06 15:57, Avri Altman wrote:
> > 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

oops, shall add it back. Thanks.

Can Guo