Re: [PATCH 10/15] usb: musb: Don't set d+ high before enable for 2430 glue layer

Tony Lindgren
2016-05-13T21:39:01Z

* Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> [160513 14:24]:
> Hi,
>
> On Fri, May 13, 2016 at 02:17:39PM -0700, Tony Lindgren wrote:
> > * Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> [160513 14:05]:
> > > Hi,
> > >
> > > On Wed, May 11, 2016 at 05:53:11PM -0700, Tony Lindgren wrote:
> > > > At least 2430 glue layer pulls d+ high on start up even if there are
> > > > no gadgets configured. This is bad at least for anything using a separate
> > > > battery charger chip as it can confuse the charger detection.
> > > >
> > > > Let's fix the issue by getting rid of omap2430_musb_set_mode() and only
> > >
> > > By doing so, you lost the feature of switching mode from sysfs, I am not
> > > sure if there is anyone using it though, still, it is a regression.
> >
> > Oh right, that's a good point.
> >
> > How about we change musb_core to call the optional set_mode() if implemented,
>
> The core already does so. Please check musb_core.h.

Oh do you have some pending patches for this already not yet
in Linux next?

> > and then set the session bit in host mode only? That way we can get rid of
> > the musb core tinkering in the glue layer drivers eventually?

So currently we have this in musb_core.h:

static inline int musb_platform_set_mode(struct musb *musb, u8 mode)
{
if (!musb->ops->set_mode)
return 0;

return musb->ops->set_mode(musb, mode);
}

What I meant is we could add generic support for the session bit:

static inline int musb_platform_set_mode(struct musb *musb, u8 mode)
{
if (!musb->ops->set_mode)
return musb_default_set_mode(musb, mode);

return musb->ops->set_mode(musb, mode);
}

Regards,

Tony