RE: [PATCH] vt_ioctl.c: fix compile error with pm_set_vt_switch()

[H Hartley Sweeten]

On Monday, September 05, 2011 7:54 AM, Arnd Bergmann wrote:
> On Saturday 03 September 2011, Alan Cox wrote:
>> On Fri, 2 Sep 2011 14:02:42 -0700
>> H Hartley Sweeten <hartleys@xxxxxxxxxxxxxxxxxxx> wrote:
>>
>>> When CONFIG_PM_SLEEP, CONFIG_VT, and CONFIG_VT_CONSOLE are not enabled
>>> the function pm_set_vt_switch() is defined as an inline in linux/suspend.h. This causes
>>> a compile error if CONFIG_VT is enabled.
>>> 
>>> drivers/tty/vt/vt_ioctl.c:1794: error: redefinition of 'pm_set_vt_switch'
>>> include/linux/suspend.h:17: error: previous definition of 'pm_set_vt_switch' was here
>>> 
>>> Fix this with an #if defined guard around the function in vt_ioctl.c.
>>
>> Can you put the #if uglies into the buggy suspend.h header instead so the
>> code proper is kept clean of ifdefs.
>
> I had discovered the same problem earlier but did not get to submit a
> fix yet. I think the patch below should do it. Hartley, can you confirm that?

Arnd,

Your patch below does appear to fix the problem.

Tested-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>


There is still a bit of #if ugliness with the pm_{prepare,restore}_console.

The source file kernel/power/console.c is compiled when CONFIG_PM_SLEEP is
enabled.  But that file ends up empty if CONFIG_VT and CONFIG_VT_CONSOLE are
not defined.

I wonder if it would be cleaner to make a new entry in kernel/power/Kconfig:

config PM_SLEEP_CONSOLE
	def_bool y
	depends on PM_SLEEP && VT && VT_CONSOLE

Then use that config option in the Makefile and in suspend.h.

Regards,
Hartley



	Arnd
---
vt/suspend: pm_set_vt_switch does not depend on CONFIG_PM_SLEEP

This avoid having multiple conflicting definitions of pm_set_vt_switch
when CONFIG_VT is set but CONFIG_PM_SLEEP or CONFIG_VT_CONSOLE are not.

drivers/tty/vt/vt_ioctl.c:1794: error: redefinition of 'pm_set_vt_switch'
include/linux/suspend.h:17: error: previous definition of 'pm_set_vt_switch' was here

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 6bbcef2..69f3b39 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -8,15 +8,18 @@
 #include <linux/mm.h>
 #include <asm/errno.h>
 
-#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE)
+#if defined(CONFIG_VT)
 extern void pm_set_vt_switch(int);
-extern int pm_prepare_console(void);
-extern void pm_restore_console(void);
 #else
 static inline void pm_set_vt_switch(int do_switch)
 {
 }
+#endif
 
+#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE)
+extern int pm_prepare_console(void);
+extern void pm_restore_console(void);
+#else
 static inline int pm_prepare_console(void)
 {
 	return 0;
--
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