[PATCH 14/38] drm/amd/display: check phy dpalt lane count config

[Bhawanpreet Lakha]

From: Lewis Huang <Lewis.Huang at amd.com>

[Why]
Type-c PHY config is not align with dpcd lane count.
When those values didn't match, it cause driver do
link training with 4 lane but phy only can output 2 lane.
The link trainig always fail.

[How]
1. Modify get_max_link_cap function. According DPALT_DP4
to update max lane count.
2. Add dp_mst_verify_link_cap to handle MST case because
we didn't call dp_mst_verify_link_cap for MST case.

Change-Id: I296933f24dff550330dd2693d348456d312d6930
Signed-off-by: Lewis Huang <Lewis.Huang at amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu at amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha at amd.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_link.c    |  3 ++-
 drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 16 ++++++++++++++++
 .../amd/display/dc/dcn10/dcn10_link_encoder.h    |  1 +
 drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h  |  3 +++
 .../gpu/drm/amd/display/dc/inc/hw/link_encoder.h |  4 ++++
 5 files changed, 26 insertions(+), 1 deletion(-)

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 552a33af0319..67462bd79179 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -872,7 +872,8 @@ bool dc_link_detect_helper(struct dc_link *link, enum dc_detect_reason reason)
 				 * empty which leads to allocate_mst_payload() has "0"
 				 * pbn_per_slot value leading to exception on dc_fixpt_div()
 				 */
-				link->verified_link_cap = link->reported_link_cap;
+				dp_verify_mst_link_cap(link);
+
 				if (prev_sink != NULL)
 					dc_sink_release(prev_sink);
 				return false;
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index 7c78caf7a602..701b73926616 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -1409,6 +1409,9 @@ static struct dc_link_settings get_max_link_cap(struct dc_link *link)
 	if (link->link_enc->features.flags.bits.IS_HBR3_CAPABLE)
 		max_link_cap.link_rate = LINK_RATE_HIGH3;
 
+	if (link->link_enc->funcs->get_max_link_cap)
+		link->link_enc->funcs->get_max_link_cap(link->link_enc, &max_link_cap);
+
 	/* Lower link settings based on sink's link cap */
 	if (link->reported_link_cap.lane_count < max_link_cap.lane_count)
 		max_link_cap.lane_count =
@@ -1670,6 +1673,19 @@ bool dp_verify_link_cap_with_retries(
 	return success;
 }
 
+bool dp_verify_mst_link_cap(
+	struct dc_link *link)
+{
+	struct dc_link_settings max_link_cap = {0};
+
+	max_link_cap = get_max_link_cap(link);
+	link->verified_link_cap = get_common_supported_link_settings(
+		link->reported_link_cap,
+		max_link_cap);
+
+	return true;
+}
+
 static struct dc_link_settings get_common_supported_link_settings(
 		struct dc_link_settings link_setting_a,
 		struct dc_link_settings link_setting_b)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_link_encoder.h b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_link_encoder.h
index 8bf5f0f2301d..0c12395cfa36 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_link_encoder.h
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_link_encoder.h
@@ -337,6 +337,7 @@ struct dcn10_link_enc_registers {
 		type RDPCS_TX_FIFO_ERROR_MASK;\
 		type RDPCS_DPALT_DISABLE_TOGGLE_MASK;\
 		type RDPCS_DPALT_4LANE_TOGGLE_MASK;\
+		type RDPCS_PHY_DPALT_DP4;\
 		type RDPCS_PHY_DPALT_DISABLE;\
 		type RDPCS_PHY_DPALT_DISABLE_ACK;\
 		type RDPCS_PHY_DP_MPLLB_V2I;\
diff --git a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h
index 08a4df2c61a8..967706e7898e 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h
@@ -43,6 +43,9 @@ bool dp_verify_link_cap_with_retries(
 	struct dc_link_settings *known_limit_link_setting,
 	int attempts);
 
+bool dp_verify_mst_link_cap(
+	struct dc_link *link);
+
 bool dp_validate_mode_timing(
 	struct dc_link *link,
 	const struct dc_crtc_timing *timing);
diff --git a/drivers/gpu/drm/amd/display/dc/inc/hw/link_encoder.h b/drivers/gpu/drm/amd/display/dc/inc/hw/link_encoder.h
index abb4e4237fb6..b21909216fb6 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/hw/link_encoder.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/hw/link_encoder.h
@@ -184,6 +184,10 @@ struct link_encoder_funcs {
 	bool (*fec_is_active)(struct link_encoder *enc);
 #endif
 	bool (*is_in_alt_mode) (struct link_encoder *enc);
+
+	void (*get_max_link_cap)(struct link_encoder *enc,
+		struct dc_link_settings *link_settings);
+
 	enum signal_type (*get_dig_mode)(
 		struct link_encoder *enc);
 };
-- 
2.17.1