ACPI: ibm-acpi: improve backlight power handling

Improve the backlight code to emulate as much as possible the power
management events, as we are unable to really power on or power off the
backlight.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/ibm_acpi.c b/drivers/acpi/ibm_acpi.c
index e7309a668732b257271ec3b9f6e176c9c7ef408d..36901362fd24418917ab0727f1450bd217d58967 100644 (file)
--- a/drivers/acpi/ibm_acpi.c
+++ b/drivers/acpi/ibm_acpi.c
@@ -86,6 +86,7 @@
 
 #include <linux/proc_fs.h>
 #include <linux/backlight.h>
+#include <linux/fb.h>
 #include <asm/uaccess.h>
 
 #include <linux/dmi.h>
@@ -1707,7 +1708,10 @@ static int brightness_write(char *buf)
 
 static int brightness_update_status(struct backlight_device *bd)
 {
-       return brightness_set(bd->props.brightness);
+       return brightness_set(
+               (bd->props.fb_blank == FB_BLANK_UNBLANK &&
+                bd->props.power == FB_BLANK_UNBLANK) ?
+                               bd->props.brightness : 0);
 }
 
 static struct backlight_ops ibm_backlight_data = {