On 2 Jun 2004, Len Brown wrote: > Has anybody seen USB interrupts increase > with no USB devices attached? Seems to be > related to Ethernet activity on a different IRQ. > > Only in IOAPIC mode; only on the VIA133/266 chipsets. > > http://bugme.osdl.org/show_bug.cgi?id=2243 > > I'm stumped. > > thanks, > -Len
Thanks a lot for posting this pointer. There have been numerous reports from users on the USB mailing lists about this same problem. And several of them have implicated some sort of network or related activity as interfering with the USB IRQ, as you've discovered. (I don't remember what chipsets they were using.) For some examples, and people who may be able to help your testing, see http://bugme.osdl.org/show_bug.cgi?id=2739 http://bugme.osdl.org/show_bug.cgi?id=2752 http://marc.theaimsgroup.com/?l=linux-usb-devel&m=108573269323454&w=2 (Plenty of others, but I haven't kept them handy.) Unforunately I can't answer your question. People post here only when they think the problem is USB-related. Turning off one of the USB IRQ lines gets their attention. But if there aren't any USB devices attached, no one would think to send a bug report here. If you're interested, I can explain why 2.6.4 started masking the USBSTS_HCH bit from the status register before testing whether to handle the interrupt. Prior to that time, I had always believed the documentation's claim that the status register was R/WC, so that writing a 1 back to the USBSTS_HCH bit would clear it. But then a user pointed out, and my own tests confirmed, that this bit was an exception. It would remain set as long as the host controller was halted, regardless of any attempts to clear it. Hence the need to mask it. If you do find a resolution, please post a pointer to it on the linux-usb-devel list. Until then, I'll recommend that people boot with "noirqdebug". Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by the new InstallShield X. >From Windows to Linux, servers to mobile, InstallShield X is the one installation-authoring solution that does it all. Learn more and evaluate today! http://www.installshield.com/Dev2Dev/0504 _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
