On 11 Nov 2009, George Spelvin wrote: > Now, here's the odd thing... > these devices lock up the NEC USB adapter: > Bus 001 Device 004: ID 1307:0165 Transcend Information, Inc. 2GB/4GB Flash Drive > > But this one doesn't: > Bus 005 Device 003: ID 0951:1603 Kingston Technology Data Traveler 1GB/2GB Pen Drive > > Ah! Because the latter is hot in high-speed mode: > /dev/sdd: > Timing cached reads: 2 MB in 2.75 seconds = 745.72 kB/sec > Timing buffered disk reads: 4 MB in 5.52 seconds = 741.76 kB/sec You shouldn't trust timing tests to tell what speed the device is running at. Look directly at the "speed" attribute file in the device's sysfs directory. Or look in the system log. > And the Transcend sometimes messes up even using the Intel motherboard USB controller: > [ 1076.501986] usb 1-4: usbfs: USBDEVFS_CONTROL failed cmd lsusb rqt 128 rq 6 len 4 ret -110 > [ 1081.490979] usb 1-4: usbfs: USBDEVFS_CONTROL failed cmd lsusb rqt 128 rq 0 len 2 ret -110 > > but that's not fatal. But it shouldn't happen. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
