linux-kernel - [PATCH AUTOSEL 5.6 068/149] drm/amd/display: always apply T7/T9 delay logic

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Message-Id: <20200411230347.22371-68-sashal@kernel.org>
Date:   Sat, 11 Apr 2020 19:02:25 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Martin Leung <martin.leung@....com>,
        Anthony Koo <Anthony.Koo@....com>,
        Rodrigo Siqueira <Rodrigo.Siqueira@....com>,
        Alex Deucher <alexander.deucher@....com>,
        Sasha Levin <sashal@...nel.org>, amd-gfx@...ts.freedesktop.org,
        dri-devel@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 5.6 068/149] drm/amd/display: always apply T7/T9 delay logic

From: Martin Leung <martin.leung@....com>

[ Upstream commit cb8348fec250e517b5facb4cab3125ddc597f9aa ]

[why]
before we exit early in edp_reciever_ready if we detect that panel
is not edp or below rev 1.2. This will skip the backlight/t7 delay panel
patch.

[how]
edit logic to ensure panel patch is applied regardless of edp rev.

Signed-off-by: Martin Leung <martin.leung@....com>
Reviewed-by: Anthony Koo <Anthony.Koo@....com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@....com>
Signed-off-by: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 .../drm/amd/display/dc/core/dc_link_hwss.c    | 56 ++++++++++---------
 1 file changed, 29 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_hwss.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_hwss.c
index ddb8550457672..58634f191a55d 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_hwss.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_hwss.c
@@ -153,18 +153,19 @@ bool edp_receiver_ready_T9(struct dc_link *link)
 	unsigned char edpRev = 0;
 	enum dc_status result = DC_OK;
 	result = core_link_read_dpcd(link, DP_EDP_DPCD_REV, &edpRev, sizeof(edpRev));
-	if (edpRev < DP_EDP_12)
-		return true;
-	/* start from eDP version 1.2, SINK_STAUS indicate the sink is ready.*/
-	do {
-		sinkstatus = 1;
-		result = core_link_read_dpcd(link, DP_SINK_STATUS, &sinkstatus, sizeof(sinkstatus));
-		if (sinkstatus == 0)
-			break;
-		if (result != DC_OK)
-			break;
-		udelay(100); //MAx T9
-	} while (++tries < 50);
+
+     /* start from eDP version 1.2, SINK_STAUS indicate the sink is ready.*/
+	if (result == DC_OK && edpRev >= DP_EDP_12) {
+		do {
+			sinkstatus = 1;
+			result = core_link_read_dpcd(link, DP_SINK_STATUS, &sinkstatus, sizeof(sinkstatus));
+			if (sinkstatus == 0)
+				break;
+			if (result != DC_OK)
+				break;
+			udelay(100); //MAx T9
+		} while (++tries < 50);
+	}
 
 	if (link->local_sink->edid_caps.panel_patch.extra_delay_backlight_off > 0)
 		udelay(link->local_sink->edid_caps.panel_patch.extra_delay_backlight_off * 1000);
@@ -183,21 +184,22 @@ bool edp_receiver_ready_T7(struct dc_link *link)
 	unsigned long long time_taken_in_ns = 0;
 
 	result = core_link_read_dpcd(link, DP_EDP_DPCD_REV, &edpRev, sizeof(edpRev));
-	if (result == DC_OK && edpRev < DP_EDP_12)
-		return true;
-	/* start from eDP version 1.2, SINK_STAUS indicate the sink is ready.*/
-	enter_timestamp = dm_get_timestamp(link->ctx);
-	do {
-		sinkstatus = 0;
-		result = core_link_read_dpcd(link, DP_SINK_STATUS, &sinkstatus, sizeof(sinkstatus));
-		if (sinkstatus == 1)
-			break;
-		if (result != DC_OK)
-			break;
-		udelay(25);
-		finish_timestamp = dm_get_timestamp(link->ctx);
-		time_taken_in_ns = dm_get_elapse_time_in_ns(link->ctx, finish_timestamp, enter_timestamp);
-	} while (time_taken_in_ns < 50 * 1000000); //MAx T7 is 50ms
+
+	if (result == DC_OK && edpRev >= DP_EDP_12) {
+		/* start from eDP version 1.2, SINK_STAUS indicate the sink is ready.*/
+		enter_timestamp = dm_get_timestamp(link->ctx);
+		do {
+			sinkstatus = 0;
+			result = core_link_read_dpcd(link, DP_SINK_STATUS, &sinkstatus, sizeof(sinkstatus));
+			if (sinkstatus == 1)
+				break;
+			if (result != DC_OK)
+				break;
+			udelay(25);
+			finish_timestamp = dm_get_timestamp(link->ctx);
+			time_taken_in_ns = dm_get_elapse_time_in_ns(link->ctx, finish_timestamp, enter_timestamp);
+		} while (time_taken_in_ns < 50 * 1000000); //MAx T7 is 50ms
+	}
 
 	if (link->local_sink->edid_caps.panel_patch.extra_t7_ms > 0)
 		udelay(link->local_sink->edid_caps.panel_patch.extra_t7_ms * 1000);
-- 
2.20.1