>>>>> *) usb devices return different descriptors at different speeds
>>>>
>>>> All tests were on usb2.
>>>> I don't have usb3 ports but I will try that at weekend.
>>>>
>>>> I'm curious now, am I the first one who has ever tested uas on usb2?
>>>
>>> Ni, I've tested it myself too, including running an entire distro
>>> with gnome3 from an uas disk.
>>>
>>> I'll also do some more tests with mkfs.ext4 with my uas disk enclosures
>>> as that seems to trigger things for you. But for me so far using usb2 is
>>> not a problem.
>>>
>>> Regards,
>>>
>>> Hans
>>
>> It looks stable with
>> can_queue = 65536 and qdepth = 32
>> on usb2.
>
> That is good to hear.
>
>> Please share you result when you have chance to test with your enclosure.
>
> I've tested 2 different uas enclosures with 3 different disks on usb2,
> running mkfs.ext4 on a single partition spanning the entire disk, and
> I could not reproduce, so this seems to be specific to the jmicron
> chipset your using. Still there is little in harm in just always reducing
> the usb2 qdepth to 32, that should be plenty to keep things close to maximum
> possible throughput on usb2.
>
> I'll write a patch for this and I'll Cc. you on the patch.
Thank you.
I could tested the device on USB 3.0 with an unpatched 3.15.5 kernel
and unfortunately it failed with the usual error.
lsusb on usb3
Bus 002 Device 002: ID 152d:0567 JMicron Technology Corp. / JMicron
USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x152d JMicron Technology Corp. / JMicron USA
Technology Corp.
idProduct 0x0567
bcdDevice 1.14
iManufacturer 1 JMicron
iProduct 2 USB to ATA/ATAPI Bridge
iSerial 3 74D781114413108
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 85
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 4 USB Mass Storage
bmAttributes 0xc0
Self Powered
MaxPower 30mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 6 MSC Bulk-Only Transport
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 1
bNumEndpoints 4
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 98
iInterface 10 MSC USB Attached SCSI
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x01 EP 1 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Command pipe (0x01)
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Status pipe (0x02)
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Data-in pipe (0x03)
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x04 EP 4 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Data-out pipe (0x04)
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 22
bNumDeviceCaps 2
USB 2.0 Extension Device Capability:
bLength 7
bDescriptorType 16
bDevCapabilityType 2
bmAttributes 0x00000002
Link Power Management (LPM) Supported
SuperSpeed USB Device Capability:
bLength 10
bDescriptorType 16
bDevCapabilityType 3
bmAttributes 0x00
wSpeedsSupported 0x000e
Device can operate at Full Speed (12Mbps)
Device can operate at High Speed (480Mbps)
Device can operate at SuperSpeed (5Gbps)
bFunctionalitySupport 1
Lowest fully-functional device speed is Full Speed (12Mbps)
bU1DevExitLat 10 micro seconds
bU2DevExitLat 32 micro seconds
Device Status: 0x0001
Self Powered
Br,
Laszlo
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