Re: [PATCH v2 06/11] phy: da8xx-usb: new driver for DA8XX SoC USB PHY

[Sergei Shtylyov]

On 04/01/2016 07:19 PM, Bin Liu wrote:

> > > > > +EXPORT_SYMBOL_GPL(da8xx_usb20_phy_set_mode);
> > > >
> > > > Don't prefer export symbols from PHY driver. That'll create unnecessary
> > > > dependencies between the controller and the PHY.
> > >
> > > Agreed.
> > >
> > > > I think it'll be better to create a new attribute and use it?
> > >
> > > Another simpler option is to not support _set_mode() for DA8xx, and the
> > > phy driver set the otgmode bit in probe() based on dr_mode of the
> > > controller.
> > >
> > > Regards,
> > > -Bin.
> >
> > This certainly works for my particular use case, however, Sergei
> > Shtylyov, who wrote the da8xx musb glue layer originally, seemed to
> > recall in his review of the patch series that this really is
> > necessary for OTG mode to work properly.
>
> I don't know much about the usb module on DA8xx, but it seems to me that
> _set_mode() has nothing to do with OTG mode.

   No, it does.

> musb_core only calls
> _set_mode() in two places - 1) sysfs: musb_mode_store(), 2) init:
> musb_init_controller(). None of them should be related to OTG mode.

   Both these places do select OTG mode.

> Regards,
> -Bin.

MBR, Sergei