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

[Alex Davis <alex14641@yahoo.com>]

>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);
> }
>

If the patch above doesn't work, try this one:

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);
 }
 
 void intel_panel_enable_backlight(struct drm_device *dev)