Re: [PATCH v7 10/23] scsi: ufs: mediatek: Handle misc host voltage regulators

[AngeloGioacchino Del Regno]

Il 24/02/26 13:38, Peter Wang (王信友) ha scritto:
> On Mon, 2026-02-16 at 14:37 +0100, Nicolas Frattaroli wrote:
> > @@ -1188,8 +1190,21 @@ static int ufs_mtk_get_supplies(struct
> > ufs_mtk_host *host)
> >   {
> >   	struct device *dev = host->hba->dev;
> >   	const struct ufs_mtk_soc_data *data =
> > of_device_get_match_data(dev);
> > +	int ret;
> > +
> > +	if (!data)
> > +		return 0;
> > +
> > +	if (data->num_reg_names) {
> > +		ret = devm_regulator_bulk_get_enable(dev, data-
> > > num_reg_names,
> > +						     data-
> > > reg_names);
>
> Hi Nicolas,
>
> If these regulators are only acquired and enabled once,
> why not just set regulator-always-on in the device tree?

Because:
 1. The UFS driver has to acquire the correct supplies regardless of them
    being on, guaranteeing both a readable power tree (sysfs/debugfs) and
    a correct hardware description in devicetree.
 2. A future update might get those regulators disabled during deep sleep

Regards,
Angelo

> Thanks
> Peter