linux-kernel - [PATCH v1 1/2] drm/msm/dp: enable HDP plugin/unplugged interrupts to hpd

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Date:   Wed, 10 May 2023 13:31:04 -0700
From:   Kuogee Hsieh <quic_khsieh@...cinc.com>
To:     <dri-devel@...ts.freedesktop.org>, <robdclark@...il.com>,
        <sean@...rly.run>, <swboyd@...omium.org>, <dianders@...omium.org>,
        <vkoul@...nel.org>, <daniel@...ll.ch>, <airlied@...il.com>,
        <agross@...nel.org>, <dmitry.baryshkov@...aro.org>,
        <andersson@...nel.org>
CC:     Kuogee Hsieh <quic_khsieh@...cinc.com>,
        <quic_abhinavk@...cinc.com>, <quic_jesszhan@...cinc.com>,
        <quic_sbillaka@...cinc.com>, <marijn.suijten@...ainline.org>,
        <freedreno@...ts.freedesktop.org>, <linux-arm-msm@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: [PATCH v1 1/2] drm/msm/dp: enable HDP plugin/unplugged interrupts to hpd_enable/disable

The internal_hpd flag was introduced to handle external DP HPD derived from GPIO
pinmuxed into DP controller. HPD plug/unplug interrupts cannot be enabled until
internal_hpd flag is set to true.
At both bootup and resume time, the DP driver will enable external DP
plugin interrupts and handle plugin interrupt accordingly. Unfortunately
dp_bridge_hpd_enable() bridge ops function was called to set internal_hpd
flag to true later than where DP driver expected during bootup time.

This causes external DP plugin event to not get detected and display stays blank.
Move enabling HDP plugin/unplugged interrupts to dp_bridge_hpd_enable()/disable() to
set internal_hpd to true along with enabling HPD plugin/unplugged interrupts
simultaneously to avoid timing issue during bootup and resume.

Fixes: cd198caddea7 ("drm/msm/dp: Rely on hpd_enable/disable callbacks")
Signed-off-by: Kuogee Hsieh <quic_khsieh@...cinc.com>
---
 drivers/gpu/drm/msm/dp/dp_display.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 3e13acdf..71aa944 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -1088,13 +1088,6 @@ static void dp_display_config_hpd(struct dp_display_private *dp)
 	dp_display_host_init(dp);
 	dp_catalog_ctrl_hpd_config(dp->catalog);
 
-	/* Enable plug and unplug interrupts only if requested */
-	if (dp->dp_display.internal_hpd)
-		dp_catalog_hpd_config_intr(dp->catalog,
-				DP_DP_HPD_PLUG_INT_MASK |
-				DP_DP_HPD_UNPLUG_INT_MASK,
-				true);
-
 	/* Enable interrupt first time
 	 * we are leaving dp clocks on during disconnect
 	 * and never disable interrupt
@@ -1396,12 +1389,6 @@ static int dp_pm_resume(struct device *dev)
 
 	dp_catalog_ctrl_hpd_config(dp->catalog);
 
-	if (dp->dp_display.internal_hpd)
-		dp_catalog_hpd_config_intr(dp->catalog,
-				DP_DP_HPD_PLUG_INT_MASK |
-				DP_DP_HPD_UNPLUG_INT_MASK,
-				true);
-
 	if (dp_catalog_link_is_connected(dp->catalog)) {
 		/*
 		 * set sink to normal operation mode -- D0
@@ -1801,15 +1788,29 @@ void dp_bridge_hpd_enable(struct drm_bridge *bridge)
 {
 	struct msm_dp_bridge *dp_bridge = to_dp_bridge(bridge);
 	struct msm_dp *dp_display = dp_bridge->dp_display;
+	struct dp_display_private *dp;
+
+	dp = container_of(dp_display, struct dp_display_private, dp_display);
 
 	dp_display->internal_hpd = true;
+	dp_catalog_hpd_config_intr(dp->catalog,
+				DP_DP_HPD_PLUG_INT_MASK |
+				DP_DP_HPD_UNPLUG_INT_MASK,
+				true);
 }
 
 void dp_bridge_hpd_disable(struct drm_bridge *bridge)
 {
 	struct msm_dp_bridge *dp_bridge = to_dp_bridge(bridge);
 	struct msm_dp *dp_display = dp_bridge->dp_display;
+	struct dp_display_private *dp;
+
+	dp = container_of(dp_display, struct dp_display_private, dp_display);
 
+	dp_catalog_hpd_config_intr(dp->catalog,
+				DP_DP_HPD_PLUG_INT_MASK |
+				DP_DP_HPD_UNPLUG_INT_MASK,
+				false);
 	dp_display->internal_hpd = false;
 }
 
-- 
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