projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* |
| 2 | * drivers/power/process.c - Functions for saving/restoring console. | |
| 3 | * | |
| 4 | * Originally from swsusp. | |
| 5 | */ | |
| 6 | ||
| 7 | #include <linux/vt_kern.h> | |
| 8 | #include <linux/kbd_kern.h> | |
| 9 | #include <linux/console.h> | |
| b6f448e9 | 10 | #include <linux/module.h> |
| 1da177e4 LT |
11 | #include "power.h" |
| 12 | ||
| 46cd2f32 RW |
13 | #if defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE) |
| 14 | #define SUSPEND_CONSOLE (MAX_NR_CONSOLES-1) | |
| 15 | ||
| 1da177e4 | 16 | static int orig_fgconsole, orig_kmsg; |
| b6f448e9 AS |
17 | static int disable_vt_switch; |
| 18 | ||
| 19 | /* | |
| 20 | * Normally during a suspend, we allocate a new console and switch to it. | |
| 21 | * When we resume, we switch back to the original console. This switch | |
| 22 | * can be slow, so on systems where the framebuffer can handle restoration | |
| 23 | * of video registers anyways, there's little point in doing the console | |
| 24 | * switch. This function allows you to disable it by passing it '0'. | |
| 25 | */ | |
| 26 | void pm_set_vt_switch(int do_switch) | |
| 27 | { | |
| 28 | acquire_console_sem(); | |
| 29 | disable_vt_switch = !do_switch; | |
| 30 | release_console_sem(); | |
| 31 | } | |
| 32 | EXPORT_SYMBOL(pm_set_vt_switch); | |
| 1da177e4 LT |
33 | |
| 34 | int pm_prepare_console(void) | |
| 35 | { | |
| 1da177e4 LT |
36 | acquire_console_sem(); |
| 37 | ||
| b6f448e9 AS |
38 | if (disable_vt_switch) { |
| 39 | release_console_sem(); | |
| 40 | return 0; | |
| 41 | } | |
| 42 | ||
| 1da177e4 LT |
43 | orig_fgconsole = fg_console; |
| 44 | ||
| 45 | if (vc_allocate(SUSPEND_CONSOLE)) { | |
| 46 | /* we can't have a free VC for now. Too bad, | |
| 47 | * we don't want to mess the screen for now. */ | |
| 48 | release_console_sem(); | |
| 49 | return 1; | |
| 50 | } | |
| 51 | ||
| b257bc05 AJ |
52 | if (set_console(SUSPEND_CONSOLE)) { |
| 53 | /* | |
| 54 | * We're unable to switch to the SUSPEND_CONSOLE. | |
| 55 | * Let the calling function know so it can decide | |
| 56 | * what to do. | |
| 57 | */ | |
| 58 | release_console_sem(); | |
| 59 | return 1; | |
| 60 | } | |
| 1da177e4 LT |
61 | release_console_sem(); |
| 62 | ||
| 63 | if (vt_waitactive(SUSPEND_CONSOLE)) { | |
| 64 | pr_debug("Suspend: Can't switch VCs."); | |
| 65 | return 1; | |
| 66 | } | |
| 67 | orig_kmsg = kmsg_redirect; | |
| 68 | kmsg_redirect = SUSPEND_CONSOLE; | |
| 1da177e4 LT |
69 | return 0; |
| 70 | } | |
| 71 | ||
| 72 | void pm_restore_console(void) | |
| 73 | { | |
| 1da177e4 | 74 | acquire_console_sem(); |
| b6f448e9 AS |
75 | if (disable_vt_switch) { |
| 76 | release_console_sem(); | |
| 77 | return; | |
| 78 | } | |
| 1da177e4 LT |
79 | set_console(orig_fgconsole); |
| 80 | release_console_sem(); | |
| 81 | kmsg_redirect = orig_kmsg; | |
| 1da177e4 | 82 | } |
| f7b8988f | 83 | #endif |