[PATCH v3] drm/msm/dp: populate connector of struct dp_panel

From: Kuogee Hsieh
Date: Thu Jan 06 2022 - 12:15:48 EST


We never assign struct dp_panel::connector, 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

Fixes: 7948fe12d47 ("drm/msm/dp: return correct edid checksum after corrupted edid checksum read")
Signee-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
---
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 3449d3f..40a059d 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -1499,6 +1499,7 @@ 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))
@@ -1507,6 +1508,8 @@ 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);
@@ -1524,6 +1527,8 @@ 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;
return 0;
}
--
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