On 9.3.2021 9.27, Thinh Nguyen wrote:

+ Mathias

Hi,

William Allen wrote:

quoted

I've never submitted to the mailing list before, so please excuse any
formalities that I may not be observing.
I would like to be able to use USB 3.2 Gen2x2 "SuperSpeed+²⁰Gbps"
under Linux. I've tried several different kernel versions, and have
built the kernel from the usb-next tree. All without finding proper
functionality.

I have an Ableconn PEX-UB159 USB 3.2 Gen 2x2 PCIe expansion card, with
the ASM3242 controller. This controller appears to be the only Gen2x2
capable controller that exists in commercial products- so far as I've
found. Everything appears to work, except for "SuperSpeed+²⁰Gbps" when
I plug in a capable device.
Here is the dmesg output as soon as I plug in a Gen2x2 WD P50 Black
External NVMe SSD, using an appropriate SuperSpeed+²⁰Gbps certified
cable:
5.11.2-arch1-1
--------------------
usb 7-2: new SuperSpeedPlus Gen 2 USB device number 3 using xhci_hcd
usb 7-2: New USB device found, idVendor=1058, idProduct=2642, bcdDevice=10.03
usb 7-2: New USB device strings: Mfr=2, Product=3, SerialNumber=1
usb 7-2: Product: Game Drive
usb 7-2: Manufacturer: Western Digital
usb 7-2: SerialNumber: 323130334431343030303736
scsi host11: uas
scsi 11:0:0:0: Direct-Access     WD       Game Drive       1003 PQ: 0 ANSI: 6
scsi 11:0:0:1: Enclosure         WD       SES Device       1003 PQ: 0 ANSI: 6
sd 11:0:0:0: [sdf] 3907029168 512-byte logical blocks: (2.00 TB/1.82 TiB)
sd 11:0:0:0: [sdf] Write Protect is off
sd 11:0:0:0: [sdf] Mode Sense: 57 00 10 00
sd 11:0:0:0: [sdf] Write cache: enabled, read cache: enabled, supports
DPO and FUA
sd 11:0:0:0: [sdf] Optimal transfer size 33553920 bytes
sd 11:0:0:0: [sdf] Attached SCSI disk

 When I saw commits referring to Gen2x2 in the usb-next repo, I built
off that, and also ran linux-next-git.r0.gabaf6f60176f-1 from AUR,
both giving me the same results/output:
linux-next-git.r0.gabaf6f60176f-1
----------------------------------------------
usb 5-1: new SuperSpeed Gen 1x2 USB device number 3 using xhci_hcd
usb 5-1: New USB device found, idVendor=1058, idProduct=2642, bcdDevice=10.03
usb 5-1: New USB device strings: Mfr=2, Product=3, SerialNumber=1
usb 5-1: Product: Game Drive
usb 5-1: Manufacturer: Western Digital
usb 5-1: SerialNumber: 323130334431343030303736
scsi host7: uas
scsi 7:0:0:0: Direct-Access     WD       Game Drive       1003 PQ: 0 ANSI: 6
scsi 7:0:0:1: Enclosure         WD       SES Device       1003 PQ: 0 ANSI: 6
ses 7:0:0:1: Attached Enclosure device
ses 7:0:0:1: Failed to get diagnostic page 0x1
ses 7:0:0:1: Failed to bind enclosure -19
sd 7:0:0:0: [sdf] 3907029168 512-byte logical blocks: (2.00 TB/1.82 TiB)
sd 7:0:0:0: [sdf] Write Protect is off
sd 7:0:0:0: [sdf] Mode Sense: 57 00 10 00
sd 7:0:0:0: [sdf] Write cache: enabled, read cache: enabled, supports
DPO and FUA
sd 7:0:0:0: [sdf] Optimal transfer size 33553920 bytes
sd 7:0:0:0: [sdf] Attached SCSI disk

See that it's detecting it as Gen 1x2.
The output of lsusb -t shows that it is connected at 5000M using the
uas driver. Even my much slower USB 3.1 SSDs connect at 10000M on the
exact same port.
When I attach the Gen2x2 NVMe SSD to my other 3.2 Gen2 card, it
connects at 10000M, so It seems to be directly related to a
mishandling when the Gen2x2 device gets recognized by the Gen2x2 card.

lspci output from 5.11.2-arch1-1:
-------------------------------------------
USB controller: ASMedia Technology Inc. ASM3242 USB 3.2 Host
Controller (prog-if 30 [XHCI])
Subsystem: ASMedia Technology Inc. ASM3242 USB 3.2 Host Controller
Physical Slot: 1
Flags: bus master, fast devsel, latency 0, IRQ 62, NUMA node 0
Memory at f7df0000 (64-bit, non-prefetchable) [size=32K]
Capabilities: [50] MSI: Enable- Count=1/8 Maskable- 64bit+
Capabilities: [68] MSI-X: Enable+ Count=8 Masked-
Capabilities: [78] Power Management version 3
Capabilities: [80] Express Legacy Endpoint, MSI 00
Capabilities: [c0] Subsystem: ASMedia Technology Inc. Device 0201
Capabilities: [100] Advanced Error Reporting
Capabilities: [200] Secondary PCI Express
Capabilities: [300] Latency Tolerance Reporting
Capabilities: [400] L1 PM Substates
Kernel driver in use: xhci_hcd
Kernel modules: xhci_pci

I'm happy to test anything, or file this somewhere more appropriate if
you could point me in the right direction.

Currently the usb host stack doesn't really support USB 3.2 yet, at
least the speed check part. I made some updates to handle that.

You apply these patches and test on your setup
https://patchwork.kernel.org/project/linux-usb/list/?series=427561

Hopefully Mathias will have time to review and Ack them for the next
release cycle.

Thanks for the reminder, added some comments to the series

-Mathias