Re: [PATCH v2 2/2] scsi: ufs: core: Replace hard coded vcc-off delay with a variable

[Peter Wang (王信友)]

On Thu, 2025-10-09 at 13:10 -0700, Bao D. Nguyen wrote:
> 
> +       /*
> +        * Most ufs devices require 1ms delay after vcc is powered
> off before
> +        * it can be powered on again. Set the default to 5ms. The
> platform
> +        * drivers can override this setting as needed.
> +        */
> +       hba->sleep_post_vcc_off = 5000;
> +
> 

Hi Bao,

Since 2ms is sufficient for most devices, wouldn't it make
sense to set the default value to 2ms?


>         init_completion(&hba->dev_cmd.complete);
> 
>         err = ufshcd_hba_init(hba);
> diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
> index 1d39437..ad49979 100644
> --- a/include/ufs/ufshcd.h
> +++ b/include/ufs/ufshcd.h
> @@ -1140,6 +1140,8 @@ struct ufs_hba {
>         int critical_health_count;
>         atomic_t dev_lvl_exception_count;
>         u64 dev_lvl_exception_id;
> +
> +       u32 sleep_post_vcc_off;
> 

The name sleep_post_vcc_off might be misunderstood as a 
status or a flag. I suggest changing it to a more explicit 
name, such as vcc_off_delay_ms.


Thanks
Peter