From 5be67a9f0c645b211db8fd8954215c683406e3d3 Mon Sep 17 00:00:00 2001
From: Kuogee Hsieh <quic_khsieh@quicinc.com>
Date: Tue, 18 Jan 2022 10:47:26 -0800
Subject: drm/msm/dp: populate connector of struct dp_panel
Git-commit: 5e602f5156910c7b19661699896cb6e3fb94fab9
Patch-mainline: v5.18-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

DP CTS test case 4.2.2.6 has valid edid with bad checksum on purpose
and expect DP source return correct checksum. During drm edid read,
correct edid checksum is calculated and stored at
connector::real_edid_checksum.

The problem is struct dp_panel::connector never be assigned, instead the
connector is stored in struct msm_dp::connector. When we run compliance
testing test case 4.2.2.6 dp_panel_handle_sink_request() won't have a valid
edid set in struct dp_panel::edid so we'll try to use the connectors
real_edid_checksum and hit a NULL pointer dereference error because the
connector pointer is never assigned.

Changes in V2:
-- populate panel connector at msm_dp_modeset_init() instead of at dp_panel_read_sink_caps()

Changes in V3:
-- remove unhelpful kernel crash trace commit text
-- remove renaming dp_display parameter to dp

Changes in V4:
-- add more details to commit text

Changes in v10:
--  group into one series

Changes in v11:
-- drop drm/msm/dp: dp_link_parse_sink_count() return immediately if aux read

Fixes: 7948fe12d47 ("drm/msm/dp: return correct edid checksum after corrupted edid checksum read")
Signee-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1642531648-8448-3-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/msm/dp/dp_display.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index faf542ce49fa..44d42c76c2a3 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -1482,6 +1482,7 @@ int msm_dp_modeset_init(struct msm_dp *dp_display, struct drm_device *dev,
 			struct drm_encoder *encoder)
 {
 	struct msm_drm_private *priv;
+	struct dp_display_private *dp_priv;
 	int ret;
 
 	if (WARN_ON(!encoder) || WARN_ON(!dp_display) || WARN_ON(!dev))
@@ -1490,6 +1491,8 @@ int msm_dp_modeset_init(struct msm_dp *dp_display, struct drm_device *dev,
 	priv = dev->dev_private;
 	dp_display->drm_dev = dev;
 
+	dp_priv = container_of(dp_display, struct dp_display_private, dp_display);
+
 	ret = dp_display_request_irq(dp_display);
 	if (ret) {
 		DRM_ERROR("request_irq failed, ret=%d\n", ret);
@@ -1507,6 +1510,8 @@ int msm_dp_modeset_init(struct msm_dp *dp_display, struct drm_device *dev,
 		return ret;
 	}
 
+	dp_priv->panel->connector = dp_display->connector;
+
 	priv->connectors[priv->num_connectors++] = dp_display->connector;
 
 	dp_display->bridge = msm_dp_bridge_init(dp_display, dev, encoder);
-- 
2.38.1