Re: v4.17-rc1: regressions on N900, N950

From: Pavel Machek
Date: Wed May 23 2018 - 15:19:03 EST


On Wed 2018-05-23 16:06:15, Pavel Machek wrote:
> On Wed 2018-05-23 00:56:38, Aaro Koskinen wrote:
> > Hi,
> >
> > On Tue, May 22, 2018 at 10:58:26PM +0200, Pavel Machek wrote:
> > > On Tue 2018-05-22 22:41:39, Aaro Koskinen wrote:
> > > > My device worked with v4.17-rc1 (haven't found time to test newer kernels),
> > > > but if you say the probe order is random then we must find some proper way
> > > > to express the dependency.
> > >
> > > I started bisect, but.. that will probably not be useful.
> > >
> > > If your device works ok in v4.17-rc1, it probably works in newer -rcs,
> > > too.
> >
> > Actually, my statement may be bogus... Now I tried again with -rc1
> > (and also -rc6) and it fails... But v4.16 works.
> >
> > > Thanks for the ordering hint, I'll try to figure out what is going on
> > > there.
> >
> > My bisection pointed to 6fa7324ac5489ad43c4b6351355b869bc5458bef which
> > doesn't seem to make any sense...?! So maybe there really is something
> > random stuff going on? :-(
>
> So... I did some experiments on v4.16.
>
> Swapping tsc2005@0 and lcd: acx565akm@2 entries in the dts does break
> stuff.
>
> I thought it might be due to vio regulator, but it does not appear
> so... screen still works with tsc2005 driver disabled in .config. (so
> there's noone to enable vio regulator).

Deleting tsc2005@0 entry also breaks screen.

Replacing tsc2005@0 entry with

foobar@0 {
compatible = "not really with anything";
spi-max-frequency = <6000000>;
reg = <0>;
};

still results in working touchscreen, removing any of the three fields
breaks it again.

Strange.

Pavel

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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