drm/i915: Warn if trying to poke a VLV backlight on invalid pipe
VLV/CHV have backlight controls only on pipes A and B. Bail out
without touching registers that don't exist, and print a warning.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index e18b3f4..ef646b1 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -521,6 +521,9 @@
{
struct drm_i915_private *dev_priv = dev->dev_private;
+ if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
+ return 0;
+
return I915_READ(VLV_BLC_PWM_CTL(pipe)) & BACKLIGHT_DUTY_CYCLE_MASK;
}
@@ -602,6 +605,9 @@
enum pipe pipe = intel_get_pipe_from_connector(connector);
u32 tmp;
+ if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
+ return;
+
tmp = I915_READ(VLV_BLC_PWM_CTL(pipe)) & ~BACKLIGHT_DUTY_CYCLE_MASK;
I915_WRITE(VLV_BLC_PWM_CTL(pipe), tmp | level);
}
@@ -717,6 +723,9 @@
enum pipe pipe = intel_get_pipe_from_connector(connector);
u32 tmp;
+ if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
+ return;
+
intel_panel_actually_set_backlight(connector, 0);
tmp = I915_READ(VLV_BLC_PWM_CTL2(pipe));
@@ -906,6 +915,9 @@
enum pipe pipe = intel_get_pipe_from_connector(connector);
u32 ctl, ctl2;
+ if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
+ return;
+
ctl2 = I915_READ(VLV_BLC_PWM_CTL2(pipe));
if (ctl2 & BLM_PWM_ENABLE) {
DRM_DEBUG_KMS("backlight already enabled\n");