[Intel-gfx] [PATCH 01/13] drm/i915/sdvo: Issue SetTargetOutput prior ot GetAttachedDisplays

[Ville Syrjala <ville.syrjala@linux.intel.com>]

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

I have at least one SDVO device (some Lenovo DVI-I ADD2 card,
based on Conexant CX25904) where GetAttachedDisplays returns
success but fails to report any attached displays unless wet
precede the command with a SetTargetOutput. Make it so.

I wasn't able to spot anything in the SDVO spec stating that
this should be necessary, but real world wins over spec.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_sdvo.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c b/drivers/gpu/drm/i915/display/intel_sdvo.c
index 8298a86d1334..9ac4c0b6055b 100644
--- a/drivers/gpu/drm/i915/display/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/display/intel_sdvo.c
@@ -2135,6 +2135,10 @@ intel_sdvo_detect(struct drm_connector *connector, bool force)
 	if (!INTEL_DISPLAY_ENABLED(i915))
 		return connector_status_disconnected;
 
+	if (!intel_sdvo_set_target_output(intel_sdvo,
+					  intel_sdvo_connector->output_flag))
+		return connector_status_unknown;
+
 	if (!intel_sdvo_get_value(intel_sdvo,
 				  SDVO_CMD_GET_ATTACHED_DISPLAYS,
 				  &response, 2))
-- 
2.39.3