[PATCH] fbdev: auo_k190x: avoid unused function warnings

The auo_k190x framebuffer driver encloses the power-management
functions in #ifdef CONFIG_PM, but the auok190x_suspend/resume
functions are only really used when CONFIG_PM_SLEEP is also
set, as a frequent gcc warning shows:

drivers/video/fbdev/auo_k190x.c:859:12: warning: 'auok190x_suspend' defined but not used
drivers/video/fbdev/auo_k190x.c:899:12: warning: 'auok190x_resume' defined but not used

This changes the driver to remove the #ifdef and instead mark
the functions as __maybe_unused, which is a nicer anyway, as it
provides build testing for all the code in all configurations
and is harder to get wrong.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/drivers/video/fbdev/auo_k190x.c b/drivers/video/fbdev/auo_k190x.c
index 8d2499d1cafb..9580374667ba 100644
--- a/drivers/video/fbdev/auo_k190x.c
+++ b/drivers/video/fbdev/auo_k190x.c

@@ -773,9 +773,7 @@ static void auok190x_recover(struct auok190xfb_par *par)
 /*
  * Power-management
  */
-
-#ifdef CONFIG_PM
-static int auok190x_runtime_suspend(struct device *dev)
+static int __maybe_unused auok190x_runtime_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct fb_info *info = platform_get_drvdata(pdev);

@@ -822,7 +820,7 @@ finish:
 	return 0;
 }
 
-static int auok190x_runtime_resume(struct device *dev)
+static int __maybe_unused auok190x_runtime_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct fb_info *info = platform_get_drvdata(pdev);

@@ -856,7 +854,7 @@ static int auok190x_runtime_resume(struct device *dev)
 	return 0;
 }
 
-static int auok190x_suspend(struct device *dev)
+static int __maybe_unused auok190x_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct fb_info *info = platform_get_drvdata(pdev);

@@ -896,7 +894,7 @@ static int auok190x_suspend(struct device *dev)
 	return 0;
 }
 
-static int auok190x_resume(struct device *dev)
+static int __maybe_unused auok190x_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct fb_info *info = platform_get_drvdata(pdev);

@@ -933,7 +931,6 @@ static int auok190x_resume(struct device *dev)
 
 	return 0;
 }
-#endif
 
 const struct dev_pm_ops auok190x_pm = {
 	SET_RUNTIME_PM_OPS(auok190x_runtime_suspend, auok190x_runtime_resume,

On 20/11/15 23:47, Arnd Bergmann wrote:

The auo_k190x framebuffer driver encloses the power-management
functions in #ifdef CONFIG_PM, but the auok190x_suspend/resume
functions are only really used when CONFIG_PM_SLEEP is also
set, as a frequent gcc warning shows:

drivers/video/fbdev/auo_k190x.c:859:12: warning: 'auok190x_suspend' defined but not used
drivers/video/fbdev/auo_k190x.c:899:12: warning: 'auok190x_resume' defined but not used

This changes the driver to remove the #ifdef and instead mark
the functions as __maybe_unused, which is a nicer anyway, as it
provides build testing for all the code in all configurations
and is harder to get wrong.

Applied for 4.5.

Btw, do you know if the linker will optimize the __maybe_unused funcs
away if they are not used? I presume so.

 Tomi

On Monday 07 December 2015 18:10:04 Tomi Valkeinen wrote:

On 20/11/15 23:47, Arnd Bergmann wrote:

quoted

The auo_k190x framebuffer driver encloses the power-management
functions in #ifdef CONFIG_PM, but the auok190x_suspend/resume
functions are only really used when CONFIG_PM_SLEEP is also
set, as a frequent gcc warning shows:

drivers/video/fbdev/auo_k190x.c:859:12: warning: 'auok190x_suspend' defined but not used
drivers/video/fbdev/auo_k190x.c:899:12: warning: 'auok190x_resume' defined but not used

This changes the driver to remove the #ifdef and instead mark
the functions as __maybe_unused, which is a nicer anyway, as it
provides build testing for all the code in all configurations
and is harder to get wrong.

Applied for 4.5.

Btw, do you know if the linker will optimize the __maybe_unused funcs
away if they are not used? I presume so.

The compiler does it correctly when built with -O1 or higher (we don't
support -O0), and the linker is not involved here.

	Arnd

On 07/12/15 18:16, Arnd Bergmann wrote:

On Monday 07 December 2015 18:10:04 Tomi Valkeinen wrote:

quoted

On 20/11/15 23:47, Arnd Bergmann wrote:

quoted

The auo_k190x framebuffer driver encloses the power-management
functions in #ifdef CONFIG_PM, but the auok190x_suspend/resume
functions are only really used when CONFIG_PM_SLEEP is also
set, as a frequent gcc warning shows:

drivers/video/fbdev/auo_k190x.c:859:12: warning: 'auok190x_suspend' defined but not used
drivers/video/fbdev/auo_k190x.c:899:12: warning: 'auok190x_resume' defined but not used

This changes the driver to remove the #ifdef and instead mark
the functions as __maybe_unused, which is a nicer anyway, as it
provides build testing for all the code in all configurations
and is harder to get wrong.

Applied for 4.5.

Btw, do you know if the linker will optimize the __maybe_unused funcs
away if they are not used? I presume so.

The compiler does it correctly when built with -O1 or higher (we don't
support -O0), and the linker is not involved here.

Ah, right, they were static. I was thinking of non-static functions. But
__maybe_unused is not even needed for non-static, so... Never mind =)

 Tomi