PM/gxfb: add hook to PM console layer that allows disabling of suspend VT switch

Prior to suspend, we allocate and switch to a new VT; after suspend, we switch
back to the original VT.  This can be slow, and is completely unnecessary if
the framebuffer we're using can restore video properly.

This adds a hook that allows drivers to select whether or not to do this vt
switch, and changes the gxfb driver to call this hook.  It also adds a module
param to gxfb to allow controlling of the vt switch (defaulting to no switch).

(Note: I'm not convinced that console_sem is the best way to protect this, but
we should probably have some form of locking..)

[akpm@linux-foundation.org: build fix]
Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Jordan Crouse <jordan.crouse@amd.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 13 insertions, 2 deletions

diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 1d7d4c5..a697742 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -12,11 +12,22 @@
 #include <asm/errno.h>
 
 #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE)
+extern void pm_set_vt_switch(int);
 extern int pm_prepare_console(void);
 extern void pm_restore_console(void);
 #else
-static inline int pm_prepare_console(void) { return 0; }
-static inline void pm_restore_console(void) {}
+static inline void pm_set_vt_switch(int do_switch)
+{
+}
+
+static inline int pm_prepare_console(void)
+{
+	return 0;
+}
+
+static inline void pm_restore_console(void)
+{
+}
 #endif
 
 typedef int __bitwise suspend_state_t;