backlight: Allow enable/disable of fb backlights, fixing regressions

Enabling the backlight by default appears to cause problems for many
users. This patch disables backlight controls unless explicitly
enabled by users via a module parameter. Since PMAC users are known
to work, default to enabled in that case.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/video/aty/atyfb_base.c b/drivers/video/aty/atyfb_base.c
index a7e0062233f2..00a51835fd82 100644
--- a/drivers/video/aty/atyfb_base.c
+++ b/drivers/video/aty/atyfb_base.c
@@ -308,6 +308,12 @@ static int xclk;
 static int comp_sync __devinitdata = -1;
 static char *mode;
 
+#ifdef CONFIG_PMAC_BACKLIGHT
+static int backlight __devinitdata = 1;
+#else
+static int backlight __devinitdata = 0;
+#endif
+
 #ifdef CONFIG_PPC
 static int default_vmode __devinitdata = VMODE_CHOOSE;
 static int default_cmode __devinitdata = CMODE_CHOOSE;
@@ -2575,7 +2581,7 @@ static int __devinit aty_init(struct fb_info *info)
                            | (USE_F32KHZ | TRISTATE_MEM_EN), par);
         } else
 #endif
-        if (M64_HAS(MOBIL_BUS)) {
+        if (M64_HAS(MOBIL_BUS) && backlight) {
 #ifdef CONFIG_FB_ATY_BACKLIGHT
                 aty_bl_init (par);
 #endif
@@ -3757,6 +3763,8 @@ static int __init atyfb_setup(char *options)
                         xclk = simple_strtoul(this_opt+5, NULL, 0);
                 else if (!strncmp(this_opt, "comp_sync:", 10))
                         comp_sync = simple_strtoul(this_opt+10, NULL, 0);
+                else if (!strncmp(this_opt, "backlight:", 10))
+                        backlight = simple_strtoul(this_opt+10, NULL, 0);
 #ifdef CONFIG_PPC
                 else if (!strncmp(this_opt, "vmode:", 6)) {
                         unsigned int vmode =