b6f448e99c
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>
84 lines
1.8 KiB
C
84 lines
1.8 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 <linux/module.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;
|
|
static int disable_vt_switch;
|
|
|
|
/*
|
|
* Normally during a suspend, we allocate a new console and switch to it.
|
|
* When we resume, we switch back to the original console. This switch
|
|
* can be slow, so on systems where the framebuffer can handle restoration
|
|
* of video registers anyways, there's little point in doing the console
|
|
* switch. This function allows you to disable it by passing it '0'.
|
|
*/
|
|
void pm_set_vt_switch(int do_switch)
|
|
{
|
|
acquire_console_sem();
|
|
disable_vt_switch = !do_switch;
|
|
release_console_sem();
|
|
}
|
|
EXPORT_SYMBOL(pm_set_vt_switch);
|
|
|
|
int pm_prepare_console(void)
|
|
{
|
|
acquire_console_sem();
|
|
|
|
if (disable_vt_switch) {
|
|
release_console_sem();
|
|
return 0;
|
|
}
|
|
|
|
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();
|
|
if (disable_vt_switch) {
|
|
release_console_sem();
|
|
return;
|
|
}
|
|
set_console(orig_fgconsole);
|
|
release_console_sem();
|
|
kmsg_redirect = orig_kmsg;
|
|
}
|
|
#endif
|