[PATCH 20/45] drm/amd/display: Wait edp HPD to high in detect_sink

[sunpeng.li at amd.com]

From: Dale Zhao <dale.zhao at amd.com>

[Why]
In 99% user case, edp will be post by vbios.
In 1% / current case: Lenovo don't light up edp panel in vbios
 post stage, vbios won't be lit up. Thus in dal when we init DCN
10 hw, we power up edp, then we start detect_sink, but internal
 time is too short, when we detect it, HPD is still low, so we don't
 detect the edp, and edp shows black.

[How]
When we init hw, we wait edp HPD to high after power up edp.

Signed-off-by: Dale Zhao <dale.zhao at amd.com>
Reviewed-by: Eric Yang <eric.yang2 at amd.com>
Acked-by: Leo Li <sunpeng.li at amd.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_link.c | 3 +++
 1 file changed, 3 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 be0c4b7..5e7e9ab 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -211,6 +211,9 @@ bool dc_link_detect_sink(struct dc_link *link, enum dc_connection_type *type)
 		return true;
 	}
 
+	if (link->connector_signal == SIGNAL_TYPE_EDP)
+		link->dc->hwss.edp_wait_for_hpd_ready(link, true);
+
 	/* todo: may need to lock gpio access */
 	hpd_pin = get_hpd_gpio(link->ctx->dc_bios, link->link_id, link->ctx->gpio_service);
 	if (hpd_pin == NULL)
-- 
2.7.4