| Message ID | 1641489335-20975-1-git-send-email-quic_khsieh@quicinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] drm/msm/dp: populate connector of struct dp_panel | expand |
On Thu 06 Jan 09:15 PST 2022, Kuogee Hsieh wrote: > 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 I unfortunately have no idea what test 4.2.2.6 is or how it ends up in dp_panel_handle_sink_request() with panel->connector being NULL. Your new commit message is much better, but I still would like to have something describing why this particular test case triggers this bug, how does it differ from normal execution, is it a race, does the test involve failing edid reads??? > 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@quicinc.com> > --- > 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; The placement of this assignment in msm_dp_modeset_init() makes much more sense than what you had in v1, so I think this looks good. Thanks, Bjorn > + > priv->connectors[priv->num_connectors++] = dp_display->connector; > return 0; > } > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >
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; }
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@quicinc.com> --- drivers/gpu/drm/msm/dp/dp_display.c | 5 +++++ 1 file changed, 5 insertions(+)