Re: [PATCH] soc: renesas: rmobile-sysc: fix -Wvoid-pointer-to-enum-cast warning

[Ulf Hansson]

On Wed, 27 Sept 2023 at 11:28, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>
> Hi Ulf,
>
> On Tue, Sep 26, 2023 at 1:22 PM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
> > On Mon, 18 Sept 2023 at 11:21, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> > > On Wed, Aug 30, 2023 at 10:24 AM Geert Uytterhoeven
> > > <geert@xxxxxxxxxxxxxx> wrote:
> > > > On Tue, Aug 15, 2023 at 12:11 AM Justin Stitt <justinstitt@xxxxxxxxxx> wrote:
> > > > > When building with clang 18 I see the following warning:
> > > > > |      drivers/soc/renesas/rmobile-sysc.c:193:22: warning: cast to smaller integer
> > > > > |               type 'enum pd_types' from 'const void *' [-Wvoid-pointer-to-enum-cast]
> > > > > |        193 |                 add_special_pd(np, (enum pd_types)id->data);
> > > > >
> > > > > This is due to the fact that `id->data` is a void* and `enum pd_types`
> > > > > has the size of an integer. This cast from pointer-width to int-width
> > > > > causes truncation and possible data loss. Instead, cast to `uintptr_t`
> > > > > which has the same width as void*.
> > > > >
> > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/1910
> > > > > Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> > > >
> > > > scripts/checkpatch.pl:
> > > >
> > > >     WARNING: Reported-by: should be immediately followed by Closes:
> > > > with a URL to the report
> > > >
> > > > Hence changing the Link: tag to a Closes: tag.
> > > >
> > > > > Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
> > > > > ---
> > > > > Note: It should be noted that there is likely no data loss occurring in
> > > > > this case since the enum only has a few fields. The narrowing cast from
> > > > > pointer to int will not lose any data.
> > > >
> > > > Indeed, the theoretical narrowing could only happen on a 64-bit
> > > > platform, while this driver is only used on arm32.
> > > >
> > > > Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> > > > i.e. will queue in renesas-devel for v6.7.
> > >
> > > As the Generic PM Domain providers were moved to drivers/pmdomain/
> > > in v6.6-rc2, and now have their own maintainer, I have moved this
> > > commit from renesas-drivers-for-v6.7 to renesas-pmdomain-for-v6.7[1],
> > > with s/soc/pmdomain/ in the oneline-summary.
> > >
> > > Ulf: if you prefer, you can still take this patch directly.
> > > Else I will send a PR after rc3 and/or rc5, like I do with my other
> > > renesas-<foo>-for-<version> branches.
> > > Thanks!
> >
> > Apologize for the delay, been traveling lately. Anyway, I can
> > certainly pick up the patch and carry it for v6.7. Just let me know,
> > if/when you have dropped the patch from your tree.
>
> Thanks, dropped.

Applied for next, thanks!

[...]

Kind regards
Uffe