Re: [PATCH RFC 0/8] USB Type-C alternate mode selection
From: Heikki Krogerus
Date: Thu Dec 11 2025 - 09:23:09 EST
Thu, Dec 11, 2025 at 03:40:24PM +0200, Heikki Krogerus kirjoitti:
> Without going into the code review yet, I'm okay with this in general,
> except with the artificial SID for the USB4. I still don't understand
> why do you guys think we should use that instead of an USB4 specific
> device type?
>
> I think somebody said earlier that the user space can't see the device
> type of the alt modes? If that's really the case, then I think there
> is some bigger issue here. Are you really sure that if you check the
> device type of an alternate mode for example with udevadm, it does not
> say DEVTYPE=typec_alternate_mode ?
>
> % udevadm info -q property --property=DEVTYPE /sys/bus/typec/devices/port0-partner.0
> DEVTYPE=typec_alternate_mode
Or just use grep :)
% grep DEVTYPE /sys/bus/typec/devices/port0-partner.0/uevent
DEVTYPE=typec_alternate_mode
So, if that really does not work, then there is a bug somewhere that
we obviously need to fix.
Please note that the port altmodes are now also part of the bus.
Br,
--
heikki