Re: [PATCH] ARM: imx25: provide a fixed regulator for usb phys

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

Hello,

On Mon, Sep 23, 2019 at 12:28:25PM +0200, Uwe Kleine-König wrote:
> On Wed, Jul 24, 2019 at 03:09:39PM +0200, Uwe Kleine-König wrote:
> > On Thu, Jun 27, 2019 at 03:15:10AM +0000, Peter Chen wrote:
> > >  
> > > > On 19-06-26 02:40, Peter Chen wrote:
> > > > >
> > > > > > Subject: [PATCH] ARM: imx25: provide a fixed regulator for usb phys
> > > > > >
> > > > > > The usb phys are internal to the SoC and so it their 5V supply. With
> > > > > > this regulator added explicitly the following (harmless) boot messages go away:
> > > > > >
> > > > > > 	usb_phy_generic usbphy:usb-phy@0: usbphy:usb-phy@0 supply vcc not found, using dummy regulator
> > > > > > 	usb_phy_generic usbphy:usb-phy@1: usbphy:usb-phy@1 supply vcc not found, using dummy regulator
> > > > > >
> > > > >
> > > > > To eliminate the warning message, I suggest doing below changes, as
> > > > > vcc supply is not mandatory.
> > > > >
> > > > > diff --git a/drivers/usb/phy/phy-generic.c
> > > > > b/drivers/usb/phy/phy-generic.c index a53b89be5324..01a5ff1a0515
> > > > > 100644
> > > > > --- a/drivers/usb/phy/phy-generic.c
> > > > > +++ b/drivers/usb/phy/phy-generic.c
> > > > > @@ -275,7 +275,7 @@ int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
> > > > >                 }
> > > > >         }
> > > > >
> > > > > -       nop->vcc = devm_regulator_get(dev, "vcc");
> > > > > +       nop->vcc = devm_regulator_get_optional(dev, "vcc");
> > > > 
> > > > Is the regulator optional? IMHO this shouldn't be the fix. I think the right fix is Uwe's
> > > > approach.
> > > > 
> > > 
> > > Add Felipe.
> > > 
> > > Some USB PHY's power are from the core system's power (eg, DDR), and some are
> > > fixed at the board and no switch for it. So, it is transparent for software at some cases.
> > 
> > It's not clear to me how to proceed. There are two opposing opinions and
> > I don't know enough about USB on mx25 to judge myself.
> > 
> > Felipe?
> 
> This thread is still open in my inbox. Felipe, how can I lure you into
> giving your opinion?
> 
> My original suggestion can be seen at
> https://lore.kernel.org/linux-usb/20190625100412.11815-1-u.kleine-koenig@pengutronix.de/,
> Peter's alternative is still in the quotes above. Which is the
> right/better one?

The stuff said above is still true. I'd like to put this issue on file
with "fixed in mainline", but currently this seems to be a stalemate.
because nobody cares enough :-|

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |