On Fri, 26 Mar 2004, Brian S. Stephan wrote: > Hello, > > On my desktop (UHCI USB controller, VIA chipset) I get terrible transfer > speeds with a specific device (USB 1.x). The device, a Neuros with 128 MB > flash storage, works fine on my laptop (OHCI USB, NEC controller) on a 2.6 > kernel. It also works fine on the desktop when I boot off of a 2.4.21-based > Gentoo livecd. > > The 2.6 slowness has been on a number of kernels, I noticed it when I first > got the device around 2.6.3-rc?, and has sustained through various vanilla > and mm kernels up to 2.6.5-rc2-mm3. > > To sum up what I'm working with: > Compaq laptop, OHCI, hotplug + udev, 2.6 device is fine > AMD+VIA-based desktop, UHCI, hotplug + udev, 2.6 device is very slow > AMD+VIA-based desktop, UHCI, hotplug + devfs, 2.4 livecd device is fine
Are you copying the same file to the device in your desktop tests with 2.6 and 2.4? > During the transfer USB debug tells me there are a bunch of bus resets and > command aborts, as Those messages appear because your device fails to transfer its status to the computer. The computer has to reset the device, and that can be a very time-consuming operation, especially when it fails (which it did, several times). > after a while (USB debug or not) I also get the following SCSI noise: > > SCSI error : <1 0 0 0> return code = 0x6000000 > end_request: I/O error, dev sdb, sector 1952 > Buffer I/O error on device sdb1, logical block 1920 > lost page write due to I/O error on sdb1 Those messages appear because the various error recovery strategies have all failed to work, and SCSI has given up on trying to transfer some of the information. > On the laptop, cp takes a bit (couple seconds) with umount taking at _most_ > two minutes... so I would say it's working right. And that was on a file > many orders larger than the original. What happens if you try to transfer the same file? > I have read that some VIA chipsets may be a bit buggy, but aside from this > device I haven't had any problems, and the fact it seemingly works in 2.4 > leads me to believe that it isn't (entirely, at least) the fault of the > hardware. This doesn't look like a VIA problem. At least one person has reported a problem in which his device would fail whenever he tried to write a file containing 0xffff in the last two bytes of one sector and 0xffff in the first two bytes of the next sector! Your problem might be similar to that -- data dependent. Or it might be a timing issue; 2.6 does usb-storage data transfers more quickly than 2.4. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
