PM/gxfb: add hook to PM console layer that allows disabling of suspend VT switch

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>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/video/geode/gxfb_core.c b/drivers/video/geode/gxfb_core.c
index 151d964c025a..f16c21d5bc21 100644
--- a/drivers/video/geode/gxfb_core.c
+++ b/drivers/video/geode/gxfb_core.c
@@ -29,6 +29,7 @@
 #include <linux/delay.h>
 #include <linux/fb.h>
 #include <linux/console.h>
+#include <linux/suspend.h>
 #include <linux/init.h>
 #include <linux/pci.h>
 #include <asm/geode.h>
@@ -37,6 +38,7 @@
 
 static char *mode_option;
 static int vram;
+static int vt_switch;
 
 /* Modes relevant to the GX (taken from modedb.c) */
 static const struct fb_videomode gx_modedb[] __initdata = {
@@ -382,6 +384,8 @@ static int __init gxfb_probe(struct pci_dev *pdev, const struct pci_device_id *i
         gxfb_check_var(&info->var, info);
         gxfb_set_par(info);
 
+        pm_set_vt_switch(vt_switch);
+
         if (register_framebuffer(info) < 0) {
                 ret = -EINVAL;
                 goto err;
@@ -502,5 +506,8 @@ MODULE_PARM_DESC(mode_option, "video mode (<x>x<y>[-<bpp>][@<refr>])");
 module_param(vram, int, 0);
 MODULE_PARM_DESC(vram, "video memory size");
 
+module_param(vt_switch, int, 0);
+MODULE_PARM_DESC(vt_switch, "enable VT switch during suspend/resume");
+
 MODULE_DESCRIPTION("Framebuffer driver for the AMD Geode GX");
 MODULE_LICENSE("GPL");