Re: [PATCH v1] ARM: dts: imx6sl-evk: keep sw4 always on
From: Lothar WaÃmann
Date: Wed Jul 04 2018 - 03:04:57 EST
Hi,
On Wed, 4 Jul 2018 01:42:54 +0000 Robin Gong wrote:
> 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?
>
Because they are living in the outside world on real devices.
Lothar WaÃmann