On Sun, 21 Nov 2010 15:23:53 -0700 TW <[email protected]> wrote:
> When I go to /mnt/usb1 and do a 'cp' command, after a minute or two I > get > the following error(s) --> > > 'usb 2-1.4: device descriptor read/64, error -110' > 'usb 2-1.4: new high speed USB device using ehci_hcd and > address 7' > ... > 'hub 2-1:1.0: unable to enumerate USB device on port 4' > > I unmounted the drive and did a 'fsck' command on it and it came back > with > no errors. I still got the error on copy, though. Telly, I have encountered USB problems like this several times before. The first time it turned out to be a USB extension cable that was not rated for USB 2.0. The second time it turned out to be a hardware design flaw with a cheap RS232-USB converter device which would not work with any USB extension cable, even a very short one, regardless of the quality. For those interested, avoid the translucent green or blue ones on Ebay: http://cgi.ebay.com/USB-RS232-Serial-DB9-9-Pin-Cable-Adapter-Converter-/120638649877?pt=LH_DefaultDomain_0&hash=item1c169fb615 However, the solid black ones worked fine for me: http://cgi.ebay.com/RS-232-SERIAL-USB-CONVERTER-DB9-Linux-WIN-7-VISTA-Y1-/270599066257?pt=LH_DefaultDomain_0&hash=item3f00f61291 although they appear to be Prolific PL-2303 chipset *clones*, they still seem to work fine for me with the Linux PL-2303 kernel driver. The USB intefaces built into many cameras, etc., are buggy as hell. I keep several lower, but OK, quality USB extension cables just for testing. The first order of business whenever I get a new device with USB is to see if it can work properly copying large files with md5sum verification with 2-3 3ft USB 2.0 no-name lower quality extension cables rigged in series. If it can pass that, chances are it will work fine with my single 3ft high quality cable. If you are using a PC, trying plugging the flash drive directly into a port on the USB card and see if the problem persists. If you need another cable, the ones from Geek Squad and Belkin are good and can be found at reasonable prices on Ebay. If you are using a USB hub, try taking that out of the system. If you want to try another USB card, get one with an NEC chipset. Belkin makes a good PCI USB card with an NEC chipset. Lastly, I am very disappointed by the error handling and reporting of the USB protocol and/or hardware implementations when confronted by cable-related problems. Very often, a device just totally hangs when it seems the right thing to do would be to have a graceful fallback to a lower, reliable, speed. Cheers, Mike Shell -- http://linuxfromscratch.org/mailman/listinfo/blfs-support FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page
