From: Arnd Bergmann <arnd@arndb.de>
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>,
Linus Walleij <linus.walleij@linaro.org>,
Vinod Koul <vkoul@kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
dmaengine@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
clang-built-linux <clang-built-linux@googlegroups.com>
Subject: Re: [PATCH] dma: ste_dma40: fix unneeded variable warning
Date: Fri, 12 Jul 2019 22:32:05 +0200 [thread overview]
Message-ID: <CAK8P3a25CdaJiaPNrYf3rZ85vptZvkN3Z88t=MX6NeOnTs_V3A@mail.gmail.com> (raw)
In-Reply-To: <CAKwvOd=-OE=uHCurw7VsHPUVHz9XWW7U_8vJEerGaYPii+f8RQ@mail.gmail.com>
On Fri, Jul 12, 2019 at 9:17 PM 'Nick Desaulniers' via Clang Built
Linux <clang-built-linux@googlegroups.com> wrote:
>
> On Fri, Jul 12, 2019 at 10:39 AM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > On Fri, Jul 12, 2019 at 11:13:30AM +0200, Arnd Bergmann wrote:
> > > clang-9 points out that there are two variables that depending on the
> > > configuration may only be used in an ARRAY_SIZE() expression but not
> > > referenced:
> > >
> > > drivers/dma/ste_dma40.c:145:12: error: variable 'd40_backup_regs' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration]
> > > static u32 d40_backup_regs[] = {
> > > ^
> > > drivers/dma/ste_dma40.c:214:12: error: variable 'd40_backup_regs_chan' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration]
> > > static u32 d40_backup_regs_chan[] = {
> > >
> > > Mark these __maybe_unused to shut up the warning.
> > >
> > > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>
> Thanks for the patch!
>
> >
> > Might be worth mentioning that this warning will only appear when
> > CONFIG_PM is unset (they are both used in d40_save_restore_registers).
>
> So would moving the definition into a
> #ifdef CONFIG_PM
> #endif
> block be better than __maybe_unused?
>
That would not work here, since the driver still uses ARRAY_SIZE() on
the variable.
Even more #ifdefs could solve that as well, but I don't want to spend too much
effort on this driver since it has almost no users.
Arnd
next prev parent reply other threads:[~2019-07-12 20:32 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-12 9:13 [PATCH] dma: ste_dma40: fix unneeded variable warning Arnd Bergmann
2019-07-12 17:39 ` Nathan Chancellor
2019-07-12 19:16 ` Nick Desaulniers
2019-07-12 20:32 ` Arnd Bergmann [this message]
2019-07-17 16:44 ` Linus Walleij
2019-07-22 14:24 ` Vinod Koul
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAK8P3a25CdaJiaPNrYf3rZ85vptZvkN3Z88t=MX6NeOnTs_V3A@mail.gmail.com' \
--to=arnd@arndb.de \
--cc=clang-built-linux@googlegroups.com \
--cc=dmaengine@vger.kernel.org \
--cc=linus.walleij@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=natechancellor@gmail.com \
--cc=ndesaulniers@google.com \
--cc=vkoul@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).