Re:[bisected] i915 dpms does not switch back light on

[Alex Davis <alex14641@yahoo.com>]

>Hi guys,
>
>After update from kernel 3.0.8 to 3.1 I encounter the following problem. 
>When power saving turns off the back light, key/mouse activity does not 
>turn it back on. I can turn it back on by pressing the "brightness++" key.


I've been having this problem as well. I created a patch that fixes the problem for me and others:

diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 6f56676..a9e0c7b 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -262,6 +262,8 @@ void intel_panel_disable_backlight(struct drm_device *dev)
                dev_priv->backlight_level = intel_panel_get_backlight(dev);
                dev_priv->backlight_enabled = false;
        }
+
+       intel_panel_set_backlight(dev, 0);
 }


For more info, see http://marc.info/?l=linux-kernel&m=131959957117710&w=2

I code, therefore I am