drm/tegra: vic: fix unused-function warnings

[PATCH] drm/tegra: vic: fix unused-function warnings

Posted by Arnd Bergmann 4 years, 3 months ago

From: Arnd Bergmann <arnd@arndb.de>

The use of the old-style SET_RUNTIME_PM_OPS() and
SET_SYSTEM_SLEEP_PM_OPS() macros requires function definitions
to be hidden to avoid

drivers/gpu/drm/tegra/vic.c:326:12: error: 'vic_runtime_suspend' defined but not used [-Werror=unused-function]
  326 | static int vic_runtime_suspend(struct device *dev)
      |            ^~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/tegra/vic.c:292:12: error: 'vic_runtime_resume' defined but not used [-Werror=unused-function]
  292 | static int vic_runtime_resume(struct device *dev)
      |            ^~~~~~~~~~~~~~~~~~

Use the new-style SYSTEM_SLEEP_PM_OPS() and RUNTIME_PM_OPS() instead.

Fixes: 1e15f5b911d6 ("drm/tegra: vic: Stop channel on suspend")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/gpu/drm/tegra/vic.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

I see this warning on 5.17-rc8, but did not test it on linux-next,
which may already have a fix.

diff --git a/drivers/gpu/drm/tegra/vic.c b/drivers/gpu/drm/tegra/vic.c
index 1e342fa3d27b..f56f5921a8c2 100644
--- a/drivers/gpu/drm/tegra/vic.c
+++ b/drivers/gpu/drm/tegra/vic.c
@@ -513,9 +513,8 @@ static int vic_remove(struct platform_device *pdev)
 }
 
 static const struct dev_pm_ops vic_pm_ops = {
-	SET_RUNTIME_PM_OPS(vic_runtime_suspend, vic_runtime_resume, NULL)
-	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
-				pm_runtime_force_resume)
+	RUNTIME_PM_OPS(vic_runtime_suspend, vic_runtime_resume, NULL)
+	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
 };
 
 struct platform_driver tegra_vic_driver = {
-- 
2.29.2

Re: [PATCH] drm/tegra: vic: fix unused-function warnings

Posted by Thierry Reding 4 years, 2 months ago

On Wed, Mar 16, 2022 at 07:36:47PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The use of the old-style SET_RUNTIME_PM_OPS() and
> SET_SYSTEM_SLEEP_PM_OPS() macros requires function definitions
> to be hidden to avoid
> 
> drivers/gpu/drm/tegra/vic.c:326:12: error: 'vic_runtime_suspend' defined but not used [-Werror=unused-function]
>   326 | static int vic_runtime_suspend(struct device *dev)
>       |            ^~~~~~~~~~~~~~~~~~~
> drivers/gpu/drm/tegra/vic.c:292:12: error: 'vic_runtime_resume' defined but not used [-Werror=unused-function]
>   292 | static int vic_runtime_resume(struct device *dev)
>       |            ^~~~~~~~~~~~~~~~~~
> 
> Use the new-style SYSTEM_SLEEP_PM_OPS() and RUNTIME_PM_OPS() instead.
> 
> Fixes: 1e15f5b911d6 ("drm/tegra: vic: Stop channel on suspend")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/gpu/drm/tegra/vic.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> I see this warning on 5.17-rc8, but did not test it on linux-next,
> which may already have a fix.
> 
> diff --git a/drivers/gpu/drm/tegra/vic.c b/drivers/gpu/drm/tegra/vic.c
> index 1e342fa3d27b..f56f5921a8c2 100644
> --- a/drivers/gpu/drm/tegra/vic.c
> +++ b/drivers/gpu/drm/tegra/vic.c
> @@ -513,9 +513,8 @@ static int vic_remove(struct platform_device *pdev)
>  }
>  
>  static const struct dev_pm_ops vic_pm_ops = {
> -	SET_RUNTIME_PM_OPS(vic_runtime_suspend, vic_runtime_resume, NULL)
> -	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> -				pm_runtime_force_resume)
> +	RUNTIME_PM_OPS(vic_runtime_suspend, vic_runtime_resume, NULL)
> +	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
>  };
>  
>  struct platform_driver tegra_vic_driver = {

Hi Arnd,

is this a replacement for __maybe_unused annotations that we would
typically use to address these? Is the ternary operator in PTR_IF enough
to eliminate the warning? Does that work the same way for structure
definitions as it does for conditionals where we use IS_ENABLED() to use
the compiler's DCE for improved coverage?

It looks like it, but just making sure because there's another patch
that fixes this warning by adding __maybe_unused.

Thierry

Re: [PATCH] drm/tegra: vic: fix unused-function warnings

Posted by Arnd Bergmann 4 years, 2 months ago

On Wed, Apr 6, 2022 at 3:21 PM Thierry Reding <thierry.reding@gmail.com> wrote:
> On Wed, Mar 16, 2022 at 07:36:47PM +0100, Arnd Bergmann wrote:
> >  static const struct dev_pm_ops vic_pm_ops = {
> > -     SET_RUNTIME_PM_OPS(vic_runtime_suspend, vic_runtime_resume, NULL)
> > -     SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> > -                             pm_runtime_force_resume)
> > +     RUNTIME_PM_OPS(vic_runtime_suspend, vic_runtime_resume, NULL)
> > +     SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
> >  };
> >
> >  struct platform_driver tegra_vic_driver = {
>
> Hi Arnd,
>
> is this a replacement for __maybe_unused annotations that we would
> typically use to address these? Is the ternary operator in PTR_IF enough
> to eliminate the warning? Does that work the same way for structure
> definitions as it does for conditionals where we use IS_ENABLED() to use
> the compiler's DCE for improved coverage?

Yes to all three.

> It looks like it, but just making sure because there's another patch
> that fixes this warning by adding __maybe_unused.

I sent a lot of patches in the past to add __maybe_unused, but this was
mainly because we could never come up with a good replacement.
Paul Cercueil has finally come up with a good solution, so this is how
we should do it from now on.

        Arnd