> -----Original Message-----
> From: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Sent: Tuesday, March 9, 2021 7:48
> To: linux-usb@xxxxxxxxxxxxxxx
> Cc: Michael Jamet; Yehezkel Bernat; Andreas Noever; Lukas Wunner; Limonciello,
> Mario; Christian Kellner; Benson Leung; Prashant Malani; Diego Rivas; Greg
> Kroah-Hartman; Mika Westerberg
> Subject: [PATCH 1/3] thunderbolt: Add details to router uevent
>
>
> [EXTERNAL EMAIL]
>
> Expose two environment variables for routers as part of the initial
> uevent:
>
> USB4_VERSION=1.0
> USB4_TYPE=host|device|hub
Presumably this will then show up in the uevent like this for a host controller:
DEVTYPE=thunderbolt_device
USB4_VERSION=1.0
USB4_TYPE=host
Since it's specifically for USB4, how about if you instead have new devtypes?
TBT3:
DEVTYPE=thunderbolt_device
USB4:
DEVTYPE=usb4_host|usb4_device|usb4_hub
That would at least make it clearer to userspace to make a delineation if it's
legacy device or not. I don't know if that's actually valuable information however.
>
> Userspace can use this information to expose more details about each
> connected device. Only USB4 devices have USB4_VERSION but all devices
> have USB4_TYPE.
>
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> ---
> drivers/thunderbolt/switch.c | 34 ++++++++++++++++++++++++++++++++++
> 1 file changed, 34 insertions(+)
>
> diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
> index 72b43c7c0651..a82032c081e8 100644
> --- a/drivers/thunderbolt/switch.c
> +++ b/drivers/thunderbolt/switch.c
> @@ -1827,6 +1827,39 @@ static void tb_switch_release(struct device *dev)
> kfree(sw);
> }
>
> +static int tb_switch_uevent(struct device *dev, struct kobj_uevent_env *env)
> +{
> + struct tb_switch *sw = tb_to_switch(dev);
> + const char *type;
> +
> + if (sw->config.thunderbolt_version == USB4_VERSION_1_0) {
> + if (add_uevent_var(env, "USB4_VERSION=1.0"))
> + return -ENOMEM;
> + }
> +
> + if (!tb_route(sw)) {
> + type = "host";
> + } else {
> + const struct tb_port *port;
> + bool hub = false;
> +
> + /* Device is hub if it has any downstream ports */
> + tb_switch_for_each_port(sw, port) {
> + if (!port->disabled && !tb_is_upstream_port(port) &&
> + tb_port_is_null(port)) {
> + hub = true;
> + break;
> + }
> + }
> +
> + type = hub ? "hub" : "device";
> + }
> +
> + if (add_uevent_var(env, "USB4_TYPE=%s", type))
> + return -ENOMEM;
> + return 0;
> +}
> +
> /*
> * Currently only need to provide the callbacks. Everything else is handled
> * in the connection manager.
> @@ -1860,6 +1893,7 @@ static const struct dev_pm_ops tb_switch_pm_ops = {
> struct device_type tb_switch_type = {
> .name = "thunderbolt_device",
> .release = tb_switch_release,
> + .uevent = tb_switch_uevent,
> .pm = &tb_switch_pm_ops,
> };
>
> --
> 2.30.1
