Re: Moving forward with the patches for using the bq24190 on x86 systems

[Tony Lindgren <tony@atomide.com>]

Hi,

* Liam Breck <liam@networkimprov.net> [170403 14:59]:
> On Mon, Apr 3, 2017 at 12:27 AM, Hans de Goede <hdegoede@redhat.com> wrote:
> > 1) The "power: supply: bq24190_charger: Never reset the charger chip" patch.
> >
> > Sebastian you said you would merge this after letting it sit a bit longer
> > on the list, unless any problems with it were noticed. I believe Liam
> > would prefer for this to not get merged as-is. So I see 3 options:
> >
> > a) Merge as-is (AFAIK no problems with it have been noticed)
> > b) Add a "no-reset-on-probe" boolean device property which will
> > make the driver not do a reset on probe (nor on resume)
> > c) Add a "reset-on-probe" boolean device property and make the
> > driver only do a reset on probe (and on resume) if this is set
> >
> > Sebastian, can you please pick one of these 3 options ? Then I
> > will adjust my patch as necessary and post a new version.
> 
> I've solicited Tony's input on this. He's studied the charger/driver a
> lot, and is a guru-level kernel contributor.

Hehehehe I think we're all just-trying-to-make-it-work kernel
contributors on this driver :)

My guess is that the reset is left over from missing handling of
clearing of the EN_HIZ on errors. I recall that EN_HIZ error can
happen when plugging the cable a little bit sideways to a USB hub
with loose tolerance USB connectors.

So it should be safe to limit the reset to only happen if something
like "reset-on-probe" is specified. Not sure we want to remove it
completely, maybe just add notes that reset may misbehave in
some conditions.

On the other issues I bet you guys know more than I do so no
comments from me.

Regards,

Tony