From 590eda32ee4291e3862c607f69711192a6612b03 Mon Sep 17 00:00:00 2001 From: Harry Wentland Date: Wed, 1 Aug 2018 10:48:23 -0400 Subject: [PATCH] drm/amd/display: Report non-DP display as disconnected without EDID commit 01dc285d5cd89b77686d8baef8482c58d7dc3ead upstream. [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. v2: Add Bugzilla and stable Bugzilla: https://bugs.freedesktop.org/107390 Bugzilla: https://bugs.freedesktop.org/106846 Cc: stable@vger.kernel.org Signed-off-by: Harry Wentland Acked-by: Alex Deucher Reviewed-by: Nicholas Kazlauskas Signed-off-by: Alex Deucher Signed-off-by: Greg Kroah-Hartman --- 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 2fa521812d23..8a7890b03d97 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -728,6 +728,17 @@ 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; }