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path: root/drivers/gpu/drm/i915/intel_panel.c
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Diffstat (limited to 'drivers/gpu/drm/i915/intel_panel.c')
-rw-r--r--drivers/gpu/drm/i915/intel_panel.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index cb058408c70e..cb8cfb7e0974 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -492,6 +492,7 @@ void intel_panel_set_backlight(struct intel_connector *connector, u32 level,
enum pipe pipe = intel_get_pipe_from_connector(connector);
u32 freq;
unsigned long flags;
+ u64 n;
if (!panel->backlight.present || pipe == INVALID_PIPE)
return;
@@ -502,10 +503,9 @@ void intel_panel_set_backlight(struct intel_connector *connector, u32 level,
/* scale to hardware max, but be careful to not overflow */
freq = panel->backlight.max;
- if (freq < max)
- level = level * freq / max;
- else
- level = freq / max * level;
+ n = (u64)level * freq;
+ do_div(n, max);
+ level = n;
panel->backlight.level = level;
if (panel->backlight.device)
@@ -1065,6 +1065,11 @@ int intel_panel_setup_backlight(struct drm_connector *connector)
unsigned long flags;
int ret;
+ if (!dev_priv->vbt.backlight.present) {
+ DRM_DEBUG_KMS("native backlight control not available per VBT\n");
+ return 0;
+ }
+
/* set level and max in panel struct */
spin_lock_irqsave(&dev_priv->backlight_lock, flags);
ret = dev_priv->display.setup_backlight(intel_connector);
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