Re: [PATCH 2/2] firmware: qcom: scm: fall back to kcalloc() for no SCM device bound

From: Dmitry Baryshkov
Date: Wed Sep 11 2024 - 07:55:47 EST


On Wed, Sep 11, 2024 at 01:41:58PM GMT, Bartosz Golaszewski wrote:
> On Tue, Sep 10, 2024 at 1:06 PM Dmitry Baryshkov
> <dmitry.baryshkov@xxxxxxxxxx> wrote:
> >
> > >
> > > I'm a little concerned about this check. I didn't think making SCM calls
> > > without the SCM device probed was possible until this report. We do
> > > worry about that in the downstream kernel. So, I'm not sure if this
> > > scenario is currently possible in the upstream kernel.
> >
> > MSM8960 and MSM8660 don't have SCM devices. For MSM8960 it should be
> > trivial to get it, c&p from apq8064 should. For MSM8660 it might be a
> > bit harder. But even if we add such nodes, we shouldn't break existing
> > DT files.
> >
>
> I'm wondering about how to approach an eventual refactoring and I'm
> thinking that for platforms that are known to have DTs out there
> without the node, we could exceptionally instantiate the SCM device
> when the module is loaded? And then modify the driver to require the
> provider to have an actual struct device attached.

Might make sense. We should be able to test in on APQ8060 = MSM8660.

--
With best wishes
Dmitry