Messages in this thread | | | Date | Thu, 24 Nov 2022 14:24:49 +0200 | From | Andy Shevchenko <> | Subject | Re: [PATCH v6 2/7] platform/chrome: cros_ec_typec: Purge blocking switch devlinks |
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On Thu, Nov 24, 2022 at 06:20:51PM +0800, Pin-yen Lin wrote: > From: Prashant Malani <pmalani@chromium.org> > > When using OF graph, the fw_devlink code will create links between the > individual port driver (cros-ec-typec here) and the parent device for > a Type-C switch (like mode-switch). Since the mode-switch will in turn > have the usb-c-connector (i.e the child of the port driver) as a > supplier, fw_devlink will not be able to resolve the cyclic dependency > correctly. > > As a result, the mode-switch driver probe() never runs, so mode-switches > are never registered. Because of that, the port driver probe constantly > fails with -EPROBE_DEFER, because the Type-C connector class requires all > switch devices to be registered prior to port registration. > > To break this deadlock and allow the mode-switch registration to occur, > purge all the usb-c-connector nodes' absent suppliers. This eliminates > the connector as a supplier for a switch and allows it to be probed.
...
> + /* > + * OF graph may have set up some device links with switches, since connectors have their > + * own compatible. Purge these to avoid a deadlock in switch probe (the switch mistakenly > + * assumes the connector is a supplier). > + */
A bit too long lines...
> + if (dev->of_node)
Why do you need this check?
> + device_for_each_child_node(dev, fwnode) > + fw_devlink_purge_absent_suppliers(fwnode);
-- With Best Regards, Andy Shevchenko
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