linux/kernel/power/console.c
Andrew Johnson b257bc051f [PATCH] swsusp: fix suspend when console is in VT_AUTO+KD_GRAPHICS mode
When the console is in VT_AUTO+KD_GRAPHICS mode, switching to the
SUSPEND_CONSOLE fails, resulting in vt_waitactive() waiting indefinitely or
until the task is interrupted.  This patch tests if a console switch can
occur in set_console() and returns early if a console switch is not
possible.

[akpm@linux-foundation.org: cleanup]
Signed-off-by: Andrew Johnson <ajohnson@intrinsyc.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
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>
2007-03-16 19:25:05 -07:00

59 lines
1.1 KiB
C

/*
* drivers/power/process.c - Functions for saving/restoring console.
*
* Originally from swsusp.
*/
#include <linux/vt_kern.h>
#include <linux/kbd_kern.h>
#include <linux/console.h>
#include "power.h"
#if defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE)
#define SUSPEND_CONSOLE (MAX_NR_CONSOLES-1)
static int orig_fgconsole, orig_kmsg;
int pm_prepare_console(void)
{
acquire_console_sem();
orig_fgconsole = fg_console;
if (vc_allocate(SUSPEND_CONSOLE)) {
/* we can't have a free VC for now. Too bad,
* we don't want to mess the screen for now. */
release_console_sem();
return 1;
}
if (set_console(SUSPEND_CONSOLE)) {
/*
* We're unable to switch to the SUSPEND_CONSOLE.
* Let the calling function know so it can decide
* what to do.
*/
release_console_sem();
return 1;
}
release_console_sem();
if (vt_waitactive(SUSPEND_CONSOLE)) {
pr_debug("Suspend: Can't switch VCs.");
return 1;
}
orig_kmsg = kmsg_redirect;
kmsg_redirect = SUSPEND_CONSOLE;
return 0;
}
void pm_restore_console(void)
{
acquire_console_sem();
set_console(orig_fgconsole);
release_console_sem();
kmsg_redirect = orig_kmsg;
return;
}
#endif