drm/i915/panel: Only record the backlight level when it is enabled
By tracking the current status of the backlight we can prevent recording
the value of the current backlight when we have disabled it. And so
prevent restoring it to 'off' after an unbalanced sequence of
intel_lvds_disable/enable.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=22672
Tested-by: Alex Riesen <raa.lkml@gmail.com>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 7350ec2..e00d200 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -250,3 +250,34 @@
tmp &= ~BACKLIGHT_DUTY_CYCLE_MASK;
I915_WRITE(BLC_PWM_CTL, tmp | level);
}
+
+void intel_panel_disable_backlight(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ if (dev_priv->backlight_enabled) {
+ 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)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ if (dev_priv->backlight_level == 0)
+ dev_priv->backlight_level = intel_panel_get_max_backlight(dev);
+
+ intel_panel_set_backlight(dev, dev_priv->backlight_level);
+ dev_priv->backlight_enabled = true;
+}
+
+void intel_panel_setup_backlight(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ dev_priv->backlight_level = intel_panel_get_max_backlight(dev);
+ dev_priv->backlight_enabled = dev_priv->backlight_level != 0;
+}