Re: [PATCH] drm/msm: Remove unused function arguments

[Rob Clark]

On Tue, Sep 17, 2019 at 10:14 AM Jordan Crouse <jcrouse@xxxxxxxxxxxxxx> wrote:
>
> On Mon, Sep 16, 2019 at 01:34:55PM -0700, Rob Clark wrote:
> > On Mon, Sep 16, 2019 at 1:12 PM Drew Davenport <ddavenport@xxxxxxxxxxxx> wrote:
> > >
> > > The arguments related to IOMMU port name have been unused since
> > > commit 944fc36c31ed ("drm/msm: use upstream iommu") and can be removed.
> > >
> > > Signed-off-by: Drew Davenport <ddavenport@xxxxxxxxxxxx>
> > > ---
> > > Rob, in the original commit the port name stuff was left intentionally.
> > > Would it be alright to remove it now?
> >
> > Upstream support for snapdragon has improved considerably since then,
> > it's been at least a couple years since I've had to backport drm to a
> > downstream android vendor kernel.  (And I think the downstream vendor
> > kernel is getting closer to upstream.)  So I think we can drop things
> > that were originally left in place to simplify backporting to vendor
> > kernel.
>
> Downstream has gotten close enough to the IOMMU API over the last few LTS
> cycles and nearly everything outside of a2xx that can work on a modern
> kernel will likely be using a arm-smmu-v2 or a MMU-500.  This code can happily
> go.
>
> > (Also, some of the regulator usage falls into this category.. at one
> > point the downstream kernel modeled gdsc's as regulators, but upstream
> > uses genpd.)
>
> Downstream still uses regulators. If we ever needed to use a downstream kernel
> for whatever reason we could easily hack them back in but I don't feel like this
> is a likely scenario.

ok, maybe we can keep the regulator cruft for a bit longer until
downstream moves to genpd.. with dummy-regulator, it doesn't really
hurt anything.

Do let me know if future downstream rebase moves to genpd, I suppose
after the next LTS after that would be a good time to garbage-collect
the regulator related gdsc management

BR,
-R