Save and restore the VGA state across a suspend-resume cycle. This

is particularly useful when VESA is available (either `options VESA'
or load the vesa module), as BIOSes in some notebooks may correctly
save and restore LCD panel settings using VESA in cases where calling
the video BIOS POST is not effective. On some systems it may also
be necessary to set the hw.acpi.reset_video sysctl to 0.

2 files changed, 56 insertions, 0 deletions

diff --git a/sys/dev/fb/vgareg.h b/sys/dev/fb/vgareg.h
index e26c214..4ccef40 100644
--- a/sys/dev/fb/vgareg.h
+++ b/sys/dev/fb/vgareg.h
@@ -69,6 +69,7 @@
 struct video_adapter;
 typedef struct vga_softc {
 	struct video_adapter	*adp;
+	void			*state_buf;
 #ifdef FB_INSTALL_CDEV
 	genfb_softc_t		gensc;
 #endif
diff --git a/sys/isa/vga_isa.c b/sys/isa/vga_isa.c
index 033882d..594e3d0 100644
--- a/sys/isa/vga_isa.c
+++ b/sys/isa/vga_isa.c
@@ -34,6 +34,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
+#include <sys/malloc.h>
 #include <sys/module.h>
 #include <sys/conf.h>
 #include <sys/bus.h>
@@ -159,6 +160,58 @@ isavga_attach(device_t dev)
 	return 0;
 }
 
+static int
+isavga_suspend(device_t dev)
+{
+	vga_softc_t *sc;
+	int err, nbytes;
+
+	sc = device_get_softc(dev);
+	err = bus_generic_suspend(dev);
+	if (err)
+		return (err);
+
+	/* Save the video state across the suspend. */
+	if (sc->state_buf != NULL) {
+		free(sc->state_buf, M_TEMP);
+		sc->state_buf = NULL;
+	}
+	nbytes = (*vidsw[sc->adp->va_index]->save_state)(sc->adp, NULL, 0);
+	if (nbytes <= 0)
+		return (0);
+	sc->state_buf = malloc(nbytes, M_TEMP, M_NOWAIT | M_ZERO);
+	if (sc->state_buf == NULL)
+		return (0);
+	if (bootverbose)
+		device_printf(dev, "saving %d bytes of video state\n", nbytes);
+	if ((*vidsw[sc->adp->va_index]->save_state)(sc->adp, sc->state_buf,
+	    nbytes) != 0) {
+		device_printf(dev, "failed to save state (nbytes=%d)\n",
+		    nbytes);
+		free(sc->state_buf, M_TEMP);
+		sc->state_buf = NULL;
+	}
+	return (0);
+}
+
+static int
+isavga_resume(device_t dev)
+{
+	vga_softc_t *sc;
+
+	sc = device_get_softc(dev);
+	if (sc->state_buf != NULL) {
+		if ((*vidsw[sc->adp->va_index]->load_state)(sc->adp,
+		    sc->state_buf) != 0)
+			device_printf(dev, "failed to reload state\n");
+		free(sc->state_buf, M_TEMP);
+		sc->state_buf = NULL;
+	}
+
+	bus_generic_resume(dev);
+	return 0;
+}
+
 #ifdef FB_INSTALL_CDEV
 
 static int
@@ -203,6 +256,8 @@ static device_method_t isavga_methods[] = {
 	DEVMETHOD(device_identify,	isavga_identify),
 	DEVMETHOD(device_probe,		isavga_probe),
 	DEVMETHOD(device_attach,	isavga_attach),
+	DEVMETHOD(device_suspend,	isavga_suspend),
+	DEVMETHOD(device_resume,	isavga_resume),
 
 	DEVMETHOD(bus_print_child,	bus_generic_print_child),
 	{ 0, 0 }