On Sat, 21 Jan 2006, Igor Yakushin wrote: > > Mainly you are measuring the computer's buffer > > capacity, not the transfer speed to the drive. > > Which buffer is that? Is it configurable or is it built into hardware?
It is Linux's block buffer system. As far as I know it is not configurable, and it certainly is not built into the hardware. > If it is a hardware problem it must be with the laptop because it behaves the > same way with 2 > different external drives and one memory stick that I tried. Also I > successfully use those USB > devices with other computers. However, at first glance I did not observe any > problems under > Windows (although I have spent much less time using USB under windows; what > is a good way to test > USB under Windows? I was using the same perl script under Cygwin) So my main > suspect now is Linux > that does not support my too new and exotic hardware. I am trying to decide > what to do with the > laptop: I have two weeks during which I can return it (which expire in couple > days). If it is a > hardware problem, I would think that the whole motherboard has to be changed. > I do not know for > sure but I would think that on a laptop USB is not a separate card but built > into the motherboard. > Right? A few people with 64-bit Linux systems have reported problems with USB. At this point it's impossible to tell whether it's caused by hardware issues or problems with the driver. > ======================= > However, an hour later (wow! it is the first time it worked for so long! > usually it is a matter of > minutes before it breaks) things get bad: > ======================= > Jan 21 18:08:28 orca kernel: usb 1-5: reset high speed USB device using > ehci_hcd and address 4 > Jan 21 18:08:40 orca kernel: usb 1-5: device not accepting address 4, error > -110 > Jan 21 18:08:40 orca kernel: usb 1-5: reset high speed USB device using > ehci_hcd and address 4 > Jan 21 18:08:51 orca kernel: usb 1-5: device not accepting address 4, error > -110 > Jan 21 18:08:51 orca kernel: usb 1-5: reset high speed USB device using > ehci_hcd and address 4 > Jan 21 18:09:02 orca kernel: usb 1-5: device not accepting address 4, error > -110 > Jan 21 18:09:02 orca kernel: usb 1-5: reset high speed USB device using > ehci_hcd and address 4 > Jan 21 18:09:12 orca kernel: usb 1-5: device not accepting address 4, error > -110 > Jan 21 18:09:12 orca kernel: usb 1-5: USB disconnect, address 4 > So my main question is: is it a hardware problem with the laptop or lack of > support for my > hardware in Linux? It looks like a hardware problem. However there may be more to it than that; there's no way to tell. It's also hard to tell if the problem is in the computer or the device, although your experience suggests it's in the computer. There have been some changes to the ehci-hcd driver posted recently. You could try this one and see if it helps at all: http://marc.theaimsgroup.com/?l=linux-usb-devel&m=113780678524619&w=2 Alan Stern ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=103432&bid=230486&dat=121642 _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
