diff options
| -rw-r--r-- | drivers/gpu/drm/i915/intel_lvds.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c index ab48edde4c9f..7fec70145a3d 100644 --- a/drivers/gpu/drm/i915/intel_lvds.c +++ b/drivers/gpu/drm/i915/intel_lvds.c @@ -968,6 +968,46 @@ static void intel_find_lvds_downclock(struct drm_device *dev, return; } +/* + * Enumerate the child dev array parsed from VBT to check whether + * the LVDS is present. + * If it is present, return 1. + * If it is not present, return false. + * If no child dev is parsed from VBT, it assumes that the LVDS is present. + * Note: The addin_offset should also be checked for LVDS panel. + * Only when it is non-zero, it is assumed that it is present. + */ +int lvds_is_present_in_vbt(struct drm_device *dev) +{ + struct drm_i915_private *dev_priv = dev->dev_private; + struct child_device_config *p_child; + int i, ret; + + if (!dev_priv->child_dev_num) + return 1; + + ret = 0; + for (i = 0; i < dev_priv->child_dev_num; i++) { + p_child = dev_priv->child_dev + i; + /* + * If the device type is not LFP, continue. + * If the device type is 0x22, it is also regarded as LFP. + */ + if (p_child->device_type != DEVICE_TYPE_INT_LFP && + p_child->device_type != DEVICE_TYPE_LFP) + continue; + + /* The addin_offset should be checked. Only when it is + * non-zero, it is regarded as present. + */ + if (p_child->addin_offset) { + ret = 1; + break; + } + } + return ret; +} + /** * intel_lvds_init - setup LVDS connectors on this device * @dev: drm device @@ -991,6 +1031,10 @@ void intel_lvds_init(struct drm_device *dev) if (dmi_check_system(intel_no_lvds)) return; + if (!lvds_is_present_in_vbt(dev)) { + DRM_DEBUG_KMS("LVDS is not present in VBT\n"); + return; + } /* Assume that any device without an ACPI LID device also doesn't * have an integrated LVDS. We would be better off parsing the BIOS * to get a reliable indicator, but that code isn't written yet. |