[PATCH 41/79] vt: remove power stuff from kernel/power

From: Greg Kroah-Hartman
Date: Sat Sep 19 2009 - 17:42:16 EST


From: Alan Cox <alan@xxxxxxxxxxxxxxx>

In the past someone gratuitiously borrowed chunks of kernel internal vt
code and dumped them in kernel/power. They have all sorts of deep relations
with the vt code so put them in the vt tree instead

Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/char/vt_ioctl.c | 56 +++++++++++++++++++++++++++++++++++++++++
include/linux/vt_kern.h | 1 +
kernel/power/console.c | 63 +++-------------------------------------------
3 files changed, 62 insertions(+), 58 deletions(-)

diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c
index 35ad94e..d29fbd4 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);
diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h
index f8c797d..5b53efe 100644
--- a/include/linux/vt_kern.h
+++ b/include/linux/vt_kern.h
@@ -117,4 +117,5 @@ struct vt_spawn_console {
};
extern struct vt_spawn_console vt_spawn_con;

+extern int vt_move_to_console(unsigned int vt, int alloc);
#endif /* _VT_KERN_H */
diff --git a/kernel/power/console.c b/kernel/power/console.c
index a3961b2..5187136 100644
--- a/kernel/power/console.c
+++ b/kernel/power/console.c
@@ -14,56 +14,13 @@
#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();
+ orig_fgconsole = vt_move_to_console(SUSPEND_CONSOLE, 1);
+ if (orig_fgconsole < 0)
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;
@@ -71,19 +28,9 @@ int pm_prepare_console(void)

void pm_restore_console(void)
{
- acquire_console_sem();
- if (disable_vt_switch) {
- release_console_sem();
- return;
- }
- set_console(orig_fgconsole);
- release_console_sem();
-
- if (vt_waitactive(orig_fgconsole)) {
- pr_debug("Resume: Can't switch VCs.");
- return;
+ if (orig_fgconsole >= 0) {
+ vt_move_to_console(orig_fgconsole, 0);
+ kmsg_redirect = orig_kmsg;
}
-
- kmsg_redirect = orig_kmsg;
}
#endif
--
1.6.4.2

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