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

[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

drivers/char/vt.c

+19 −1
Original line number Diff line number Diff line
@@ -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;

drivers/char/vt_ioctl.c

+1 −1
Original line number Diff line number Diff line
@@ -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)

include/linux/kbd_kern.h

+1 −1
Original line number Diff line number Diff line
@@ -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)

include/linux/vt_kern.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

kernel/power/console.c

+9 −1
Original line number Diff line number Diff line
@@ -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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