diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_panel.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_panel.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index 01b5a519c43..a43c33bc4a3 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -494,8 +494,11 @@ void intel_panel_set_backlight(struct drm_device *dev, u32 level, u32 max) goto out; } - /* scale to hardware */ - level = level * freq / max; + /* scale to hardware, but be careful to not overflow */ + if (freq < max) + level = level * freq / max; + else + level = freq / max * level; dev_priv->backlight.level = level; if (dev_priv->backlight.device) @@ -512,6 +515,17 @@ void intel_panel_disable_backlight(struct drm_device *dev) struct drm_i915_private *dev_priv = dev->dev_private; unsigned long flags; + /* + * Do not disable backlight on the vgaswitcheroo path. When switching + * away from i915, the other client may depend on i915 to handle the + * backlight. This will leave the backlight on unnecessarily when + * another client is not activated. + */ + if (dev->switch_power_state == DRM_SWITCH_POWER_CHANGING) { + DRM_DEBUG_DRIVER("Skipping backlight disable on vga switch\n"); + return; + } + spin_lock_irqsave(&dev_priv->backlight.lock, flags); dev_priv->backlight.enabled = false; |