On Thu, 18 Mar 2004, Malcolm Blaney wrote: > Alan Stern wrote: > > There's nothing obviously wrong here. You can try using the patch for > > Linux 2.6.4 below, which will print out information to the system log when > > certain key events occur. Also, you should make sure the log is echoed to > > your console so you don't lose anything when the system hangs. Set the > > console log level up very high. > > I changed the console log level, and checked the output from 2.6.2 > again. It prints more than I managed to get from dmesg before, so > thought I better make the correction. On plugging in a usb device, > before it hangs I actually get: > drivers/usb/host/uhci-hcd.c: c400: wakeup_hc > hub 1-0:1.0: port 1, status 101, change 1, 12 Mb/s > hub 1-0:1.0: debounce: port 1: delay 100ms stable 4 status 0x101 > hub 1-0:1.0: new USB device on port 1, assigned address 2 > > Using your patch with the 2.6.4 kernel I get: > uhci irq status: 0x24 > usb 1-1: new full speed USB device using address 2 > uhci enqueue: ce1eb5a0 > uhci fsbr enabled
That certainly looks like things go wrong just at the time the full-speed bandwidth reclamation gets turned on. Why should FSBR cause any problems? The only thing that occurs to me now is that with FSBR, the UHCI controller starts making some heavy demands on the PCI bus. Maybe it's somehow managing to mess up or monopolize the bus. Why should this only show up under Linux 2.6 and not other operating systems? I don't know -- maybe there's a difference in some aspect of the PCI configuration. > While I'm here, I also found that the working boards we have (a 400MHz > model) also run slowly when using the old uhci.c driver with the 2.4.18 > kernel. Going to the 2.4.19 kernel, this driver runs fast. So I thought > this might help me with the 600MHz board I'm having trouble with, since > they have the same VIA VT82C686A chip. Can anyone tell me of any > functional changes that occurred at that time? I don't know if it's > related, but I'm looking into it anyway. I don't know what changed. 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
