* [PATCH v3] drm/msm/dp: populate connector of struct dp_panel
@ 2022-01-06 17:15 Kuogee Hsieh
2022-01-06 17:56 ` Bjorn Andersson
0 siblings, 1 reply; 2+ messages in thread
From: Kuogee Hsieh @ 2022-01-06 17:15 UTC (permalink / raw)
To: robdclark, sean, swboyd, vkoul, daniel, airlied, agross,
dmitry.baryshkov, bjorn.andersson
Cc: quic_sbillaka, linux-arm-msm, quic_abhinavk, dri-devel,
quic_khsieh, aravindh, freedreno, linux-kernel
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(+)
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;
}
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v3] drm/msm/dp: populate connector of struct dp_panel
2022-01-06 17:15 [PATCH v3] drm/msm/dp: populate connector of struct dp_panel Kuogee Hsieh
@ 2022-01-06 17:56 ` Bjorn Andersson
0 siblings, 0 replies; 2+ messages in thread
From: Bjorn Andersson @ 2022-01-06 17:56 UTC (permalink / raw)
To: Kuogee Hsieh
Cc: quic_sbillaka, quic_abhinavk, airlied, freedreno, vkoul,
dri-devel, swboyd, agross, linux-arm-msm, dmitry.baryshkov,
aravindh, sean, linux-kernel
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
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2022-01-06 17:15 [PATCH v3] drm/msm/dp: populate connector of struct dp_panel Kuogee Hsieh
2022-01-06 17:56 ` Bjorn Andersson
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