[Intel-gfx] [PATCH v2] drm/i915: Fake HDMI live status

[Shashank Sharma]

This patch does the following:
- Fakes live status of HDMI as connected (even if that's not).
  While testing certain (monitor + cable) combinations with
  various intel  platforms, it seems that live status register
  doesn't work reliably on some older devices. So limit the
  live_status check for HDMI detection, only for platforms
  from gen7 onwards.

This fixes regression added by patch:
  'commit 237ed86c693d ("drm/i915: Check live status before reading edid")'

V2: restrict faking live_status to certain platforms

Based on suggestion by: Ville Syrjala<ville.syrjala at linux.intel.com>
Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
---
 drivers/gpu/drm/i915/intel_hdmi.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index b199ede..c2150db 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1412,8 +1412,16 @@ intel_hdmi_detect(struct drm_connector *connector, bool force)
 				hdmi_to_dig_port(intel_hdmi));
 	}
 
-	if (!live_status)
-		DRM_DEBUG_KMS("Live status not up!");
+	/*
+	* Live status reg is not reliable for all older platforms
+	* So for certain platforms, dont block EDID read even if
+	* live_status is down, give EDID a shot.
+	*/
+	if ((INTEL_INFO(dev_priv)->gen < 7 || IS_IVYBRIDGE(dev_priv))
+		&& !live_status) {
+		DRM_DEBUG_KMS("Warning: live status not up, faking it\n");
+		live_status = true;
+	}
 
 	intel_hdmi_unset_edid(connector);
 
-- 
1.9.1