On Tue, 13 Jul 2004, Daniel Miller (IMI) wrote: > I've got a machine here with a custom-designed 12-port USB 2.0 interface on > it. It has three NEC 720101 host controllers, with four sockets > (individually powerable) off of each controller. We're using kernel 2.4.26. > At one point we thought we had all of this working successfully. However, > we've found that after running for a number of hours, the machine tends to > lock up on us. We do not use usb-storage, because we need to be able to > claim interfaces via libusb, in order to run some operations. The sequence > of operations that we do in this current test loop is thus: > > 1. power up all sockets, one at a time, with 500 msec pause between each > socket power-up > 2. poll /proc/bus/usb/devices until the last-modified date hasn't changed > for several seconds. The reason for this is to keep us from trying to start > claiming interfaces before the core drivers have detected all the devices. > 3. claim_interface() on each installed device. > 4. read some USB data from the device > 5. release all devices > 6. power down all sockets, one at a time, with 100 msec pause between each > 7. sleep(4) (this was added as part of debug, but didn't impact the > problem) > 8. repeat steps 1 through 7 until the machine crashes > > What I'm finding is that the system will run these tests for anywhere from 3 > to 20 hours, but then at some point it just hangs. The entire computer > hangs, not just a process. There are no indications ahead of time that > anything is going wrong. From examining /var/log/messages, I've found that > the hang always occurs during the USB core discovery processes, before any > of my polling code ever gets executed; any number of devices may have been > discovered when it hangs, from a minimum of one to a maximum of seven or > eight.
Does Alt-SysRq-T work when the system is hung? Have you considered running your tests under Linux 2.6.current? Alan Stern ------------------------------------------------------- This SF.Net email sponsored by Black Hat Briefings & Training. Attend Black Hat Briefings & Training, Las Vegas July 24-29 - digital self defense, top technical experts, no vendor pitches, unmatched networking opportunities. Visit www.blackhat.com _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
