Bug 211681 - Titan Ridge usb-c 8086:15ec capped to 480 Mb/s on Macmini8,1
Summary: Titan Ridge usb-c 8086:15ec capped to 480 Mb/s on Macmini8,1
Status: NEW
Alias: None
Product: Platform Specific/Hardware
Classification: Unclassified
Component: x86-64 (show other bugs)
Hardware: Intel Linux
: P1 high
Assignee: platform_x86_64@kernel-bugs.osdl.org
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2021-02-10 16:40 UTC by Harald Rudell
Modified: 2024-02-19 05:44 UTC (History)
1 user (show)

See Also:
Kernel Version: 5.8.0-36-generic
Subsystem:
Regression: No
Bisected commit-id:

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Description Harald Rudell 2021-02-10 16:40:43 UTC 
Ubuntu 20.04 on Macmini8,1 Mac mini (2018) 
2xusb-a ports off Cannon Lake works at 5 Gb/s
4xusb-c ports of Titan Ridge 4C 2018: 10 Gb/s inoperative, only slower devices are detected

dmesg --human --follow does not detect devices being plugged in if the device selects a speed higher than 480 Mb/s


lspci -knns7e:
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:
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

        ​ lspci -knns14.0
        ​ 00:14.0 USB controller [0c03]: Intel Corporation Cannon Lake PCH USB 3.1 xHCI Host Controller [8086:a36d] (rev 10)
        ​         Subsystem: Intel Corporation Cannon Lake PCH USB 3.1 xHCI Host Controller [8086:7270]
        ​         Kernel driver in use: xhci_hcd
        ​         Kernel modules: xhci_pci
Comment 1 Harald Rudell 2021-03-24 19:55:46 UTC 
It appears Intel did not bother implementing usb3 bus speeds for Titan Ridge 4C 2018 in their Linux driver that is delivered with the kernel

The world is screwed

https://01.org/ does not respond to inquiries
Comment 2 Harald Rudell 2021-03-24 19:57:46 UTC 
At least in the Apple implementation that may have a unique way of addressing DMA security
This chip is also used by Dell an others
Comment 3 Harald Rudell 2021-12-18 23:06:37 UTC 
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
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