Alan, here is the requested information. Sorry for the delay.
Started usbmon log with no connected USB devices:
$ sudo cat /sys/kernel/debug/usb/usbmon/0u | tee usbmon.txt
...
See the attached usbmon.txt.gz
Timing:
Connect of flash drive at: 16:09:04
dmesg output after connect of flash drive:
[ 421.660488] usb 2-2: new SuperSpeed USB device number 3 using xhci_hcd
[ 421.677113] usb 2-2: New USB device found, idVendor=05dc, idProduct=a212
[ 421.677116] usb 2-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 421.677118] usb 2-2: Product: USB Flash Drive
[ 421.677119] usb 2-2: Manufacturer: Lexar
[ 421.677121] usb 2-2: SerialNumber: 0C5E8B182D1D474C
[ 421.861807] usb-storage 2-2:1.0: USB Mass Storage device detected
[ 421.862034] scsi host2: usb-storage 2-2:1.0
[ 421.862194] usbcore: registered new interface driver usb-storage
[ 421.865557] usbcore: registered new interface driver uas
[ 422.861240] scsi 2:0:0:0: Direct-Access Lexar USB Flash
Drive PMAP PQ: 0 ANSI: 6
[ 422.862053] sd 2:0:0:0: Attached scsi generic sg1 type 0
[ 422.863780] sd 2:0:0:0: [sdb] 125173760 512-byte logical blocks:
(64.1 GB/59.7 GiB)
[ 422.864287] sd 2:0:0:0: [sdb] Write Protect is off
[ 422.864343] sd 2:0:0:0: [sdb] Mode Sense: 2b 00 00 08
[ 422.864864] sd 2:0:0:0: [sdb] Write cache: disabled, read cache:
enabled, doesn't support DPO or FUA
[ 423.150473] sd 2:0:0:0: [sdb] Attached SCSI removable disk
lsusb -t at: 16:10:21
$ lsusb -t
/: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/3p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/8p, 480M
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M
|__ Port 2: Dev 3, If 0, Class=Mass Storage, Driver=usb-storage,
5000M <-- the flash drive
|__ Port 3: Dev 2, If 0, Class=Hub, Driver=hub/4p, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/9p, 480M
|__ Port 3: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 2: Dev 4, If 0, Class=Wireless, Driver=btusb, 12M
|__ Port 2: Dev 4, If 1, Class=Wireless, Driver=btusb, 12M
|__ Port 4: Dev 6, If 0, Class=Vendor Specific Class, Driver=, 12M
|__ Port 7: Dev 9, If 0, Class=Video, Driver=uvcvideo, 480M
|__ Port 7: Dev 9, If 1, Class=Video, Driver=uvcvideo, 480M
dd at: 16:11:50
$ sudo dd if=/dev/zero of=/dev/sdb bs=1M count=256
256+0 records in
256+0 records out
268435456 bytes (268 MB, 256 MiB) copied, 5,84305 s, 45,9 MB/s
On Tue, May 31, 2016 at 5:15 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
> On Tue, 31 May 2016, Michael Schaller wrote:
>
>> Is there anything else I can do to debug this issue further?
>> Are there any quirks I could try?
>
> You can try capturing a usbmon trace of a test transfer. That might
> provide a clue about where the bottleneck lies.
>
> Also, post the dmesg log showing what happens when you plug in the
> drive.
>
> Alan Stern
>
>> On Wed, May 18, 2016 at 3:41 PM, Michael Schaller <misch@xxxxxxxxxx> wrote:
>> > [1.] One line summary of the problem:
>> > Slow writes with dd on Lexar JumpDrive P20 64GB flash drives connected
>> > via Intel USB 3.0 host controllers.
>> >
>> >
>> > [2.] Full description of the problem/report:
>> > Writes on Lexar JumpDrive P20 64GB flash drives are unexpectedly slow.
>> > With dd we are seeing 45 MB/s while we get the expected 270 MB/s under
>> > Mac OS X and Windows. This issue is present on all tested flash drives
>> > of this type and on multiple machines with various Intel USB 3.0 host
>> > controllers (the data in this report is from a HP EliteBook 840).
>> > Furthermore the issue is present with kernel 4.6 and older kernels
>> > (tested with 4.4, 4.2, 3.19 and 3.13). The dmesg output doesn't
>> > contain any errors and other than the slow write speed there are no
>> > issues and no oops'.
>> >
>> > Write speed under Linux:
>> > $ sudo dd if=/dev/zero of=/dev/sdb bs=1M count=256
>> > 256+0 records in
>> > 256+0 records out
>> > 268435456 bytes (268 MB) copied, 5.98705 s, 44.8 MB/s
>> >
>> > Write speed under Mac OS X:
>> > $ sudo dd if=/dev/zero of=/dev/rdisk2 bs=1048576 count=256
>> > 256+0 records in
>> > 256+0 records out
>> > 268435456 bytes transferred in 0.941998 secs (284963933 bytes/sec)
>
Attachment:
usbmon.txt.gz
Description: GNU Zip compressed data
