Re: [PATCH v2 9/9] ASoC: tegra_sgtl5000: fix platform name vs. of_node assignement

From: Marcel Ziswiler
Date: Wed Oct 17 2018 - 17:33:08 EST


On Wed, 2018-10-17 at 20:16 +0100, Mark Brown wrote:
> On Wed, Oct 17, 2018 at 02:28:22PM +0000, Marcel Ziswiler wrote:
>
> > Some questions:
> > - How exactly are devm allocations supposed to work concerning
> > probe
> > deferrals?
>
> Probe deferrals are just normal probe errors, any devm_ allocated
> stuff
> gets unwound.

OK, that is where my understanding was weary. So you are saying
anything should really get allocated again upon the second time.

> > - Does or should the platform get cleared during a probe deferral
> > cycle?
> > - If so, why does that not work?
>
> Is something writing to static data when it should be writing to
> dynamically allocated data? That's what this sounds like, we
> shouldn't
> be modifying any static data and any data dynamically allocated
> during
> probe ought to be being discarded.

OK, I believe I start to see what you are saying. I guess the bug lays
in soc-core then not properly discarding the platform and the second
time around it is using a stale pointer to that which now of course
points to whatever happens to be there! Let me try a few more things
and I will cook up a proper patch to fix that...

> > - Or is some special implicit probe deferral handling missing in
> > soc-
> > core?
>
> Like I say a probe deferral is just a normal error.

Yeah, right. Thanks!