On Wed, 14 Mar 2007, Casey Ballentine wrote: > Hello, > > I'm trying to troubleshoot a problem with a custom USB device based on > the Atmel AT43USB326 chip. The device is a simple keypad and > integrated audio device for use by the visually impaired. On Windows > XP the keypad and audio devices are recognized and I can use Wordpad > (ugh) to see that the key events from the keypad are received. On both > a Linux From Scratch (kernel 2.6.16.18) and Fedora Core 6 > (2.6.19-1.2895.fc6) install, however the keypad and audio devices > aren't recognized and I get the following dmesg output: > > usb 1-1: new full speed USB device using uhci_hcd and address 2 > usb 1-1: configuration #1 chosen from 1 choice > hub 1-1:1.0: USB hub found > hub 1-1:1.0: config failed, hub has too many ports! (err -19) > > I've recompiled my LFS 2.6.16.18 kernel for usb verbose debug and > usbmon support. Attached please find the dmesg, /proc/bus/usb/devices, > and usbmon output when plugging in the device.
Very interesting. The critical part of the usbmon log is this: dd63a4c0 3538778184 S Ci:005:00 s 80 06 0302 0409 00ff 255 < dd63a4c0 3538782142 C Ci:005:00 0 48 = 30034d00 75006c00 74006900 6d006500 64006900 61002000 4b006500 79006200 dd63a4c0 3538782785 S Ci:005:00 s a0 06 2900 0000 000d 13 < dd63a4c0 3538785139 C Ci:005:00 0 9 = 30034d00 75006c00 74 The first two lines are a Get-String-Descriptor request followed by its reply. The last two lines are a Get-Hub-Descriptor request and its reply. Notice that the so-called hub descriptor is nothing of the kind! In fact, it is the first 9 bytes of the previous string descriptor. It may seem odd that the device sent back 9 bytes when the request was for 13 bytes and the string descriptor's length is 48. However 9 is a reasonable length for a hub descriptor. Evidently the device sent back the contents of the wrong buffer. Alan Stern ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Linux-usb-users@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
