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Commit 7cf4f69d authored by Zhao Yakui's avatar Zhao Yakui Committed by Eric Anholt
Browse files

drm/i915: Don't set up the LVDS if it isn't in the BIOS device table. 



We not only check the device type, but also check the addin_offset. If the
addin_offset is zero, it won't be initialized.

Signed-off-by: default avatarZhao Yakui <yakui.zhao@intel.com>
Reviewed-by: default avatarAdam Jackson <ajax@redhat.com>
Signed-off-by: default avatarEric Anholt <eric@anholt.net>
[anholt: hand-applied due to conflicts]
parent ae266c98

drivers/gpu/drm/i915/intel_lvds.c

+44 −0
Original line number Diff line number Diff line
@@ -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.