On 08/01/2018 03:51 PM, Harry Wentland wrote:

[Why] Some boards seem to have a problem where HPD is high on HDMI even though no display is connected. We don't want to report these as connected. DP spec still requires us to report DP displays as connected when HPD is high but we can't read the EDID in order to go to fail-safe mode.

[How] If connector_signal is not DP abort detection if we can't retrieve the EDID.

Bugzilla: https://bugs.freedesktop.org/107390 Bugzilla: https://bugs.freedesktop.org/106846 Cc: stable@vger.kernel.org Signed-off-by: Harry Wentland harry.wentland@amd.com Acked-by: Alex Deucher alexander.deucher@amd.com

v2: Add Bugzilla and stable

drivers/gpu/drm/amd/display/dc/core/dc_link.c | 11 +++++++++++ 1 file changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c index b180197a41e2..84f0fd15be4c 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -744,6 +744,17 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason) break; case EDID_NO_RESPONSE: DC_LOG_ERROR("No EDID read.\n");

• 	/*
  

• 	 * Abort detection for non-DP connectors if we have
  

• 	 * no EDID
  

• 	 *
  

• 	 * DP needs to report as connected if HDP is high
  

• 	 * even if we have no EDID in order to go to
  

• 	 * fail-safe mode
  

• 	 */
  

• 	if (!dc_is_dp_signal(link->connector_signal))
  

• 		return false;
  

  default: break; }

Reviewed-by: Nicholas Kazlauskas nicholas.kazlauskas@amd.com