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The Mac mini (2018) Macmini8,1 is running Linux with rEFInd. The mini has 2 usb-a 10 Gb/s ports, and 4 usb-c 10 Gb/s ports

Problem: On usb-c ports, "dangerous" devices are not recognized by the kernel, they are ignored on plugin like nothing happened

"dangerous" devices include storage Samsung T5/T7 or networking Realtek 8153

"safe" devices like mouse, keyboard and display works

Everything works on usb-a ports

uname --kernel-release 
5.8.0-36-generic

to run with T2:

  • applesmc brcmfmac blacklisted
  • tg3 so buggy it is not used
  • csrutil disable
  • Startup Security Utility: No Security, Allow booting from external or removable media

How can any type USB device be made to work on usb-c ports?

February 1, 2021: it is discovered that only devices that decide to use 480 Mb/s or slower work. No device selecting 5 or 10 Gb/s will appear in dmesg --human --follow

February 5, 2021:

The usb ports that are capped at 480 Mb/s are off the Thunderbolt controllers:

lspci -knns7e:0
7e:00.0 USB controller [0c03]: Intel Corporation JHL7540 Thunderbolt 3 USB Controller [Titan Ridge 4C 2018] [8086:15ec] (rev 06)
    Subsystem: Intel Corporation JHL7540 Thunderbolt 3 USB Controller [Titan Ridge 4C 2018] [8086:0000]
    Kernel driver in use: xhci_hcd
    Kernel modules: xhci_pci
lspci -knns8:0
08:00.0 USB controller [0c03]: Intel Corporation JHL7540 Thunderbolt 3 USB Controller [Titan Ridge 4C 2018] [8086:15ec] (rev 06)
    Subsystem: Intel Corporation JHL7540 Thunderbolt 3 USB Controller [Titan Ridge 4C 2018] [8086:0000]
    Kernel driver in use: xhci_hcd
    Kernel modules: xhci_pci    ​
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  • Apple's Mac mini (2018) - Technical Specifications state "Two USB-A ports (up to 5Gb/s)".
    – David Anderson
    Jan 15, 2021 at 23:52
  • Linux reports 10000 ie. 10 Gb/s on usb-a ports. Capable devices plugged in claims to operate at 10 Gb/s. The Intel hardware is capable of 10 Gb/s. Please comment if there is a solution to the problem, otherwise refrain
    – Keith
    Jan 16, 2021 at 1:06
  • You already stated mice, keyboards and displays work. Therefore, you have answered your own question. Is this just about running Linux on your Mac? Can you be more specific about the version of Linux? What does csrutil disable have to do with Linux?
    – David Anderson
    Jan 16, 2021 at 3:35
  • There are several devices that are recognized only on usb-a ports, not on usb-c ports. I am therefore losing 40 Gb/s of usb bandwidth and 45 W of usb power
    – Keith
    Jan 27, 2021 at 20:10
  • Correction: lsusb --tree: the two usb-a devices available claiming 10 Gb/s only connects at 5 Gb/s on usb-a but 10 Gb/s on usb-c while the hub claims 10 Gb/s. So there is also a loss of 10 Gb/s peak speeds. Linux is Ubuntu linux-generic-hwe-20.04
    – Keith
    Jan 27, 2021 at 20:43

1 Answer 1

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What is not working is hotplug of any device 5+ Gb/s on Apple computers with Intel cpu, 2016+

At boot time, devices are recognized by efi firmware. After that, any unplugged device is gone until again plugged in during boot

https://bugzilla.kernel.org/show_bug.cgi?id=211681

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1914845

Mac mini (2018) Macmini8,1 Linux usb-c will not recognize certain usb device types

https://www.reddit.com/r/Gentoo/comments/mlkc57/usb_drive_only_detected_when_attached_at_boot/

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