Commit b257bc05 authored by Andrew Johnson's avatar Andrew Johnson Committed by Linus Torvalds

[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: default avatarAndrew Johnson <ajohnson@intrinsyc.com>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1174cf73
......@@ -2185,10 +2185,28 @@ static void console_callback(struct work_struct *ignored)
release_console_sem();
}
void set_console(int nr)
int set_console(int nr)
{
struct vc_data *vc = vc_cons[fg_console].d;
if (!vc_cons_allocated(nr) || vt_dont_switch ||
(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
/*
* Console switch will fail in console_callback() or
* change_console() so there is no point scheduling
* the callback
*
* Existing set_console() users don't check the return
* value so this shouldn't break anything
*/
return -EINVAL;
}
want_console = nr;
schedule_console_callback();
return 0;
}
struct tty_driver *console_driver;
......
......@@ -34,7 +34,7 @@
#include <linux/kbd_diacr.h>
#include <linux/selection.h>
static char vt_dont_switch;
char vt_dont_switch;
extern struct tty_driver *console_driver;
#define VT_IS_IN_USE(i) (console_driver->ttys[i] && console_driver->ttys[i]->count)
......
......@@ -75,7 +75,7 @@ extern int do_poke_blanked_console;
extern void (*kbd_ledfunc)(unsigned int led);
extern void set_console(int nr);
extern int set_console(int nr);
extern void schedule_console_callback(void);
static inline void set_leds(void)
......
......@@ -83,6 +83,7 @@ void reset_vc(struct vc_data *vc);
#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE)
extern char con_buf[CON_BUF_SIZE];
extern struct semaphore con_buf_sem;
extern char vt_dont_switch;
struct vt_spawn_console {
spinlock_t lock;
......
......@@ -27,7 +27,15 @@ int pm_prepare_console(void)
return 1;
}
set_console(SUSPEND_CONSOLE);
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)) {
......
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