Change in libgfxinit[master]: gma: actually enable/disable backlight with new backlight control

[Nico Huber (Code Review)]

Nico Huber has submitted this change. ( https://review.coreboot.org/c/libgfxinit/+/48770 )

Change subject: gma: actually enable/disable backlight with new backlight control
......................................................................

gma: actually enable/disable backlight with new backlight control

In order to enable or disable the backlight on platforms with the new
backlight control, both enable bits in the PWM register and the
PP_CONTROL register need to bet set. Currently, the code only sets one
or the other.

Also, reverse the order in the disable case so that PWM gets disabled
after the backlight enable bit in PP_CONTROL.

Tested successfully on Clevo L141CU (CML).

Change-Id: Ib3827e744e86a9d29e09da3c5fd44d226f0b41b5
Signed-off-by: Michael Niewöhner 
Reviewed-on: https://review.coreboot.org/c/libgfxinit/+/48770
Tested-by: Nico Huber 
Reviewed-by: Nico Huber 
Reviewed-by: Angel Pons 
---
M common/hw-gfx-gma-panel.adb
1 file changed, 8 insertions(+), 8 deletions(-)

Approvals:
  Nico Huber: Verified; Looks good to me, approved
  Angel Pons: Looks good to me, approved

diff --git a/common/hw-gfx-gma-panel.adb b/common/hw-gfx-gma-panel.adb
index e343deb..532bf67 100644
--- a/common/hw-gfx-gma-panel.adb
+++ b/common/hw-gfx-gma-panel.adb
@@ -428,11 +428,11 @@
          Registers.Set_Mask
            (Register => BLC (Panel).CTL,
             Mask     => BXT_BLC_PWM_CTL_ENABLE);
-      else
-         Registers.Set_Mask
-           (Register => PP (Panel).CONTROL,
-            Mask     => PCH_PP_CONTROL_BACKLIGHT_ENABLE);
       end if;
+
+      Registers.Set_Mask
+        (Register => PP (Panel).CONTROL,
+         Mask     => PCH_PP_CONTROL_BACKLIGHT_ENABLE);
    end Backlight_On;

procedure Backlight_Off (Panel : Panel_Control) is
@@ -443,14 +443,14 @@

pragma Debug (Debug.Put_Line (GNAT.Source_Info.Enclosing_Entity));

+     Registers.Unset_Mask
+       (Register => PP (Panel).CONTROL,
+        Mask     => PCH_PP_CONTROL_BACKLIGHT_ENABLE);
+
       if Config.Has_New_Backlight_Control then
          Registers.Unset_Mask
            (Register => BLC (Panel).CTL,
             Mask     => BXT_BLC_PWM_CTL_ENABLE);
-      else
-         Registers.Unset_Mask
-           (Register => PP (Panel).CONTROL,
-            Mask     => PCH_PP_CONTROL_BACKLIGHT_ENABLE);
       end if;
    end Backlight_Off;