Re: [PATCH v4 04/12] scsi: ufs: core: Add support for TX Equalization

[Can Guo <can.guo@oss.qualcomm.com>]

Hi Peter,

On 3/24/2026 3:46 PM, Peter Wang (王信友) wrote:
>
> On Fri, 2026-03-20 at 20:10 -0700, Can Guo wrote:
> > +static int ufshcd_tx_eqtr(struct ufs_hba *hba,
> > +                         struct ufshcd_tx_eq_params *params,
> > +                         struct ufs_pa_layer_attr *pwr_mode)
> > +{
> > +       struct ufs_pa_layer_attr old_pwr_info;
> > +       u32 gear = pwr_mode->gear_tx;
> > +       int ret;
> > +
> > +       if (gear < UFS_HS_G4 || gear > UFS_HS_G6) {
> > +               dev_err(hba->dev, "TX EQTR is not implemented for HS-
> > G%u\n",
> > +                       gear);
> > +               return -EINVAL;
> > +       }
> > 
>
> Hi Can,
>
> This check can be removed since ufshcd_config_tx_eq_settings
> has already checked it.
OK.
>
>
> > +       params = &hba->tx_eq_params[gear - 1];
> > +
> > +       if (gear < UFS_HS_G1 || gear > UFS_HS_GEAR_MAX) {
> > +               dev_err(hba->dev, "Invalid HS-Gear (%u) for TX
> > Equalization\n",
> > +                       gear);
> > +               return -EINVAL;
> > +       } else if (gear < adaptive_txeq_gear) {
> > +               return 0;
> > +       }
> > 
>
> "gear" should be checked before use?
I don't understand this comment.
>
> > +       /* TX EQTR is supported for HS-G4 and higher Gears */
> > +       if (gear < UFS_HS_G4)
> > +               goto apply_tx_eq_settings;
> > +
>
> Could we return 0 directly?
> and move this to the previous check, like this:
> } else if (gear < max_t(u32, adaptive_txeq_gear, UFS_HS_G4) {
> return 0;
> }
Sounds good.

Thanks,
Can Guo.
>
> Thanks
> Peter
>
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