| Message ID | 20230112042104.4107253-3-treapking@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Register Type-C mode-switch in DP bridge endpoints | expand |
On Thu, Jan 12, 2023 at 12:20:57PM +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. > > Signed-off-by: Prashant Malani <pmalani@chromium.org> > Signed-off-by: Pin-yen Lin <treapking@chromium.org> > Reviewed-by: Chen-Yu Tsai <wenst@chromium.org> > Tested-by: Chen-Yu Tsai <wenst@chromium.org> FWIW: Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > --- > > Changes in v10: > - Collected Reviewed-by and Tested-by tags > > Changes in v7: > - Fix the long comment lines > > Changes in v6: > - New in v6 > > drivers/platform/chrome/cros_ec_typec.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c > index 2a7ff14dc37e..302474a647cc 100644 > --- a/drivers/platform/chrome/cros_ec_typec.c > +++ b/drivers/platform/chrome/cros_ec_typec.c > @@ -382,6 +382,16 @@ static int cros_typec_init_ports(struct cros_typec_data *typec) > return -EINVAL; > } > > + /* > + * 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). > + */ > + if (dev_of_node(dev)) > + device_for_each_child_node(dev, fwnode) > + fw_devlink_purge_absent_suppliers(fwnode); > + > /* DT uses "reg" to specify port number. */ > port_prop = dev->of_node ? "reg" : "port-number"; > device_for_each_child_node(dev, fwnode) { > -- > 2.39.0.314.g84b9a713c41-goog
diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c index 2a7ff14dc37e..302474a647cc 100644 --- a/drivers/platform/chrome/cros_ec_typec.c +++ b/drivers/platform/chrome/cros_ec_typec.c @@ -382,6 +382,16 @@ static int cros_typec_init_ports(struct cros_typec_data *typec) return -EINVAL; } + /* + * 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). + */ + if (dev_of_node(dev)) + device_for_each_child_node(dev, fwnode) + fw_devlink_purge_absent_suppliers(fwnode); + /* DT uses "reg" to specify port number. */ port_prop = dev->of_node ? "reg" : "port-number"; device_for_each_child_node(dev, fwnode) {