Now that I know wisdomlight has the issue too on their Macbook Air <https://lists.gnu.org/archive/html/help-guix/2020-01/msg00105.html> I investigated further.
>From the Linux kernel docs <https://www.kernel.org/doc/html/latest/input/devices/bcm5974.html>: > 5.2. USB Race > > The Apple multi-touch trackpads report both mouse and keyboard events > via different interfaces of the same usb device. This creates a race > condition with the HID driver, which, if not told otherwise, will find > the standard HID mouse and keyboard, and claim the whole device. To > remedy, the usb product id must be listed in the mouse_ignore list of > the hid driver. Indeed for me on good boots, the command `lsusb -t` prints |__ Port 3: Dev 2, If 2, Class=Human Interface Device, Driver=bcm5974, 12M while on bad boots it says Driver=usbmouse. But why that happens I do not know, because the mouse_ignore list in the Linux-libre kernel’s drivers/hid/hid-quirks.c file does list my touchpad. Strange. I will investigate further if a change to the kernel config could help. Regards, Florian
