diff options
Diffstat (limited to 'drivers/char/vt_ioctl.c')
| -rw-r--r-- | drivers/char/vt_ioctl.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c index 35ad94e65d0d..d29fbd44bdca 100644 --- a/drivers/char/vt_ioctl.c +++ b/drivers/char/vt_ioctl.c @@ -16,6 +16,7 @@ #include <linux/tty.h> #include <linux/timer.h> #include <linux/kernel.h> +#include <linux/module.h> #include <linux/kd.h> #include <linux/vt.h> #include <linux/string.h> @@ -1483,3 +1484,58 @@ void change_console(struct vc_data *new_vc) complete_change_console(new_vc); } + +/* Perform a kernel triggered VT switch for suspend/resume */ + +static int disable_vt_switch; + +int vt_move_to_console(unsigned int vt, int alloc) +{ + int prev; + + acquire_console_sem(); + /* Graphics mode - up to X */ + if (disable_vt_switch) { + release_console_sem(); + return 0; + } + prev = fg_console; + + if (alloc && vc_allocate(vt)) { + /* 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 -ENOSPC; + } + + if (set_console(vt)) { + /* + * 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 -EIO; + } + release_console_sem(); + if (vt_waitactive(vt)) { + pr_debug("Suspend: Can't switch VCs."); + return -EINTR; + } + return prev; +} + +/* + * 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); |