Re: [PATCH v1] ARM: dts: imx6sl-evk: keep sw4 always on

From: Robin Gong
Date: Tue Jul 03 2018 - 21:43:03 EST


On ä, 2018-07-03 at 08:10 -0300, Fabio Estevam wrote:
> Hi Anson,
>
> On Tue, Jul 3, 2018 at 4:44 AM, Anson Huang <anson.huang@xxxxxxx>
> wrote:
>
> >
> > It is NOT easy to identify which switch is critical or NOT, and
> > different platforms
> > have different board design, it will introduce many platform
> > specified code, so I think
> > just revert the pfuze100 switch enable/disable patch should be OK
> > for now.
> I have sent the pfuze100 regulator patch revert and it is linux-next
> now. Should probably reach 4.18-rc4.
>
> >
> > After a couple of release cycles, add the pfuze100 switch
> > enable/disable patch
> > back to support this feature, I believe users should switch to new
> > dtb with "regulator-always-on"
> > existing already.
> That will still break old dtb compatibility.
>
> You cannot force users to use "regulator-always-on" and the old dtbs
> need to always work.
>
> So whatever new feature you need to introduce it needs to be done in
> such a way that the existing dtb's will continue working.
But actually existing dtb is not right since the critical power rail
missing 'regulator-always-on'. It's a fix patch for dts, not related
with following dtb/kernel break rules, just a simple dts patch. Why
should we make promise for the wrong dtbs?