** Description changed: Certain USB devices do not work properly, or do not work at all, while the ehci_hcd module is loaded. A solution is to unload the ehci_hcd module, which is loaded every time the computer starts, using the command 'sudo modprobe -r ehci_hcd'. This works fine but unfortunatly ehci-hcd is necessary for using USB 2.0, so you lose USB 2.0 features. Another solution is to disable USB 2.0 through the BIOS setup. With some devices it is possible to read files normally (ie. copy files from an USB pendrive to the computer), but the device disconnects abrubtly when you start writing data on the device. In some devices it fails after writing a certain amount of data, probably the size of the write cache. Steps to reproduce: 1. Insert your USB 2.0 device (like a flash drive) 2. If the device is recognised and mounted properly try copying a file to it. 3. Comfirm with the 'dmesg' command that it isn't functioning properly. (I/O errors etc) 4. Remove the USB device 5. Unload ehci_hcd with 'sudo modprobe -r ehci_hcd' 6. Insert your USB device again. 7. Check that everything works. (copy some files, etc.) + + A disproportionate number of individuals report Alcor chipsets in the problematic behavior. See: + https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/88746/comments/62 + https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/88746/comments/119 + https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/88746/comments/299 + https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/88746/comments/397 + http://bugzilla.kernel.org/show_bug.cgi?id=ehci_hcd + + Noted Workarounds: + https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/88746/comments/372
** Tags added: alcor -- ehci_hcd module causes I/O errors in USB 2.0 devices https://bugs.launchpad.net/bugs/88746 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
