On 06/16/2017 02:11 AM, Eric Anholt wrote:
If the panel-bridge is being set up after the drm_mode_config_reset(),
then the connector's state would never get initialized, and we'd
dereference the NULL in the hotplug path. We also need to register
the connector, so that userspace can get at it.
Shouldn't the KMS driver make sure the panel-bridge is set up before
drm_mode_config_reset? Is it the case when we're inserting the
panel-bridge driver as a module?
All the connectors that have been added are registered automatically
when drm_dev_register() is called by the KMS driver. Registering a
connector in the middle of setting up our driver is prone to race
conditions if the userspace decides to use them immediately.
Thanks,
Archit
Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
---
drivers/gpu/drm/bridge/panel.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c
index 67fe19e5a9c6..8ed8a70799c7 100644
--- a/drivers/gpu/drm/bridge/panel.c
+++ b/drivers/gpu/drm/bridge/panel.c
@@ -82,11 +82,14 @@ static int panel_bridge_attach(struct drm_bridge *bridge)
drm_mode_connector_attach_encoder(&panel_bridge->connector,
bridge->encoder);
+ drm_atomic_helper_connector_reset(&panel_bridge->connector);
ret = drm_panel_attach(panel_bridge->panel, &panel_bridge->connector);
if (ret < 0)
return ret;
+ drm_connector_register(&panel_bridge->connector);
+
return 0;
}
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