[Intel-gfx] [PATCH] Also write to bl_power when setting brightness.

[Matthias Hopf]

Switches backlight on/off on controllers that support this api.
---
 src/drmmode_display.c |   25 +++++++++++++++++++++++--
 1 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/drmmode_display.c b/src/drmmode_display.c
index 4fb20d9..f41b978 100644
--- a/src/drmmode_display.c
+++ b/src/drmmode_display.c
@@ -109,6 +109,12 @@ static char *backlight_interfaces[] = {
 /* Enough for 10 digits of backlight + '\n' + '\0' */
 #define BACKLIGHT_VALUE_LEN 12
 
+/* Constants from include/linux/fb.h */
+enum {
+	FB_BLANK_UNBLANK   = 0,
+	FB_BLANK_POWERDOWN = 4
+};
+
 static void
 drmmode_backlight_set(xf86OutputPtr output, int level)
 {
@@ -121,22 +127,37 @@ drmmode_backlight_set(xf86OutputPtr output, int level)
     if (! drmmode_output->backlight_iface || level < 0)
 	return;
 
-    len = snprintf(val, BACKLIGHT_VALUE_LEN, "%d\n", level);
     sprintf(path, "%s/%s/brightness",
 	    BACKLIGHT_CLASS, drmmode_output->backlight_iface);
+    len = snprintf(val, BACKLIGHT_VALUE_LEN, "%d\n", level);
     fd = open(path, O_RDWR);
     if (fd == -1) {
 	xf86DrvMsg(output->scrn->scrnIndex, X_ERROR, "failed to open %s for backlight "
 		   "control: %s\n", path, strerror(errno));
 	return;
     }
-
     ret = write(fd, val, len);
     if (ret == -1) {
 	xf86DrvMsg(output->scrn->scrnIndex, X_ERROR, "write to %s for backlight "
 		   "control failed: %s\n", path, strerror(errno));
     }
+    close(fd);
 
+    sprintf(path, "%s/%s/bl_power",
+	    BACKLIGHT_CLASS, drmmode_output->backlight_iface);
+    len = snprintf(val, BACKLIGHT_VALUE_LEN, "%d\n",
+		   level > 0 ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN);
+    fd = open(path, O_RDWR);
+    if (fd == -1) {
+	xf86DrvMsg(output->scrn->scrnIndex, X_ERROR, "failed to open %s for backlight "
+		   "control: %s\n", path, strerror(errno));
+	return;
+    }
+    ret = write(fd, val, len);
+    if (ret == -1) {
+	xf86DrvMsg(output->scrn->scrnIndex, X_ERROR, "write to %s for backlight "
+		   "control failed: %s\n", path, strerror(errno));
+    }
     close(fd);
 }
 
-- 
1.6.0.2