Re: [PATCH v4 07/12] scsi: ufs: core: Add support to retrain TX Equalization via debugfs

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

On 3/22/2026 9:36 PM, Bean Huo wrote:
> On Fri, 2026-03-20 at 20:10 -0700, Can Guo wrote:
>> +/**
>> + * ufshcd_retrain_tx_eq - Retrain TX Equalization and apply new settings
>> + * @hba: per-adapter instance
>> + * @gear: target High-Speed (HS) gear for retraining
>> + *
>> + * This function initiates a refresh of the TX Equalization settings for a
>> + * specific HS gear. It scales the clocks to maximum frequency, negotiates
>> the
>> + * power mode with the device, retrains TX EQ and applies new TX EQ settings
>> + * by conducting a Power Mode change.
>> + *
>> + * Returns 0 on success, non-zero error code otherwise
>> + */
>> +int ufshcd_retrain_tx_eq(struct ufs_hba *hba, u32 gear)
>> +{
>> +       struct ufs_pa_layer_attr new_pwr_info, final_params = {};
>> +       int ret;
>> +
>> +       if (!ufshcd_is_tx_eq_supported(hba) || !use_adaptive_txeq)
>> +               return -EOPNOTSUPP;
>> +
>> +       if (gear < adaptive_txeq_gear)
>> +               return -ERANGE;
>> +
>> +       ufshcd_hold(hba);
>> +
>> +       ret = ufshcd_pause_command_processing(hba, 1 * USEC_PER_SEC);
>> +       if (ret) {
>> +               ufshcd_release(hba);
>> +               return ret;
>> +       }
>> +
>> +       /* scale up clocks to max frequency before TX EQTR */
>> +       if (ufshcd_is_clkscaling_supported(hba))
>> +               ufshcd_scale_clks(hba, ULONG_MAX, true);
>> +
>> +       new_pwr_info = hba->pwr_info;
>> +       new_pwr_info.gear_tx = gear;
>> +       new_pwr_info.gear_rx = gear;
>> +
>> +       ret = ufshcd_vops_negotiate_pwr_mode(hba, &new_pwr_info,
>> &final_params);
>> +       if (ret)
>> +               memcpy(&final_params, &new_pwr_info, sizeof(final_params));
>> +
>> +       if (final_params.gear_tx != gear) {
>> +               dev_err(hba->dev, "Negotiated Gear (%u) does not match target
>> Gear (%u)\n",
>> +                       final_params.gear_tx, gear);\
> might be ret = -EINVAL; before goto?
You are right, let me add it in next version.

Thanks,
Can Guo.
>
>
>> +               goto out;
>> +       }