Dear Maintainer,
On MacBook Pros with a T1 chip (2016-2017 Touch Bar models, USB ID
05ac:8600), the udev rule shipped in 1.1.1 sets bConfigurationValue to 0
for the T1 when it appears:
SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device",
ENV{PRODUCT}=="5ac/12[9a][0-9a-f]/*|5ac/8600/*", ACTION=="add",
ENV{USBMUX_SUPPORTED}="1", ATTR{bConfigurationValue}="0", ...
That deconfigures the T1, so all of its interfaces go away: the Touch Bar,
the ambient light sensor and the FaceTime camera. On a MacBookPro14,2
running Ubuntu 26.04 (usbmuxd 1.1.1-7, the Debian package unchanged), the
T1 had no active configuration after boot (bConfigurationValue empty);
later in the session it was found in configuration 3 instead of the
normal configuration 1, apparently selected by usbmuxd. The source in sid
(1.1.1-7) has the same rule.
Upstream fixed this in 2023:
commit 61b99ab5c2
"udev: Make sure iBridge (T1) doesn't end up in an unconfigured state"
https://github.com/libimobiledevice/usbmuxd/commit/61b99ab5c2
It removes 5ac/8600 from the "set configuration 0" rule and adds a
separate rule that sets configuration 1 for the T1 instead. No usbmuxd
release contains it yet (1.1.1 is from 2020), so I would like to ask for
it to be added as a patch to the Debian package. Ubuntu syncs usbmuxd from
Debian, so the fix would reach Ubuntu as well.
Steps to reproduce:
1. On a 2016/2017 MacBook Pro with Touch Bar, install usbmuxd 1.1.1-7.
2. Reboot.
3. cat /sys/bus/usb/devices/<T1 port>/bConfigurationValue -> empty;
lsusb -t shows no interfaces under 05ac:8600.
Workaround: copy /lib/udev/rules.d/39-usbmuxd.rules to /etc/udev/rules.d/
and remove "|5ac/8600/*" from its rules.