How can I check whether USB3.0 UASP (USB Attached SCSI Protocol) mode is enabled in Linux?
If you know the name of your device, find the USB Bus and Device numbers:
$ lsusb
...
Bus 002 Device 005: ID xxxx:yyyy MyDeviceManufacturer
...
Then look at the USB tree and find your device (mine was Bus 2, Dev 5):
$ lsusb -t
...
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/6p, 5000M
|__ Port 2: Dev 5, If 0, Class=Mass Storage, Driver=uas, 5000M
|__ Port 4: Dev 3, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
...
You can see in my case the uas
driver.
If UAS is not in use you would see usb-storage
(like Dev 3 in my case).
In addition to the answer austinmarton gave, you can run
lsusb -v -d VPID | grep -i interface
where VPID is the vendor/product ID reported in lsusb
. For example:
$ lsusb -v -d 1234:5678 | grep -i interface
Couldn't open device, some information will be missing
bDeviceClass 0 (Defined at Interface level)
bNumInterfaces 1
Interface Descriptor:
bInterfaceNumber 0
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 6
Notice that the only bInterfaceProtocol
value listed is 80 Bulk-Only
. This device would not be a UASP-configured device. However, if you see an additional bInterfaceProtocol 98
, this would be a UASP-configured device.
These values are given in decimal, but the spec refers to them by their hex values...
50h (80d): USB Mass Storage Class Bulk-Only (BBB) Transport
62h (98d): Allocated by USB-IF for UAS.
This information can be found in the Mass Storage Specification on usb.org, section 3 Protocol Codes, Table 2 — Mass Storage Transport Protocol.
I'm not sure if this answers your first or second questions, though, since it's unclear if this value would be reported on both machines/devices that do support UASP and those that do not.
To complete the answer:
If your controller does not support UAS, the linux kernel is kind enough to tell you so:
$ dmesg | grep "UAS"
[58669.959610] usb 4-2: USB controller 0000:03:00.0 does not support streams, which are required by the UAS driver.
[58669.959613] usb 4-2: Please try an other USB controller if you wish to use UAS.
Also, lsusb shows a line for bInterfaceProtocol 98, but it is empty:
$ lsusb -v -d 0080:a001 | grep -i interface
bDeviceClass 0 (Defined at Interface level)
bNumInterfaces 1
Interface Descriptor:
bInterfaceNumber 0
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 0
Interface Descriptor:
bInterfaceNumber 0
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 98
iInterface 0
HTH,
R. Daneel olivaw,
The Human Robot Inside.