On Wed, 1 Apr 2009, Tilman Schmidt wrote: > A user of the bas_gigaset driver reports that while his Logitech Laser > Wireless mouse is connected to the system via USB, ISDN connections > are regularly killed every 30 seconds by the clock. Regularly every 30 seconds? That sounds surprisingly reproducible. > Debugging output > from the driver shows that the two tasklets read_iso_tasklet and > write_iso_tasklet handling the isochronous B channel send and receive > data streams are simultaneously not run for an entire inter-packet > interval, ie. 8 milliseconds. Disconnecting the mouse from USB and > connecting it to the PS/2 mouse port instead makes the effect stop. > > Platform is Debian Lenny 64 bit, kernel 2.6.26, on a Gigabyte > GA-EP45T-EXTREME Motherboard with an Intel Core Duo E8600 @ 3.3 GHz. > Beside the Gigaset and mouse, there's a keyboard, printer and UPS > connected via USB, but those don't seem to interfere. > > Applying a patch I have in my pipeline to schedule these two critical > tasklets with tasklet_hi_schedule() did not help. > > Any idea what might be the cause of that problem and how to avoid it? I'm not aware of anything in the USB stack that would prevent tasklets from running. A very long-lasting interrupt handler might do it, but I don't know of any such handlers. This is only a far-fetched guess... Is the mouse connected through a USB hub? If it is, does connecting it directly to the computer change anything? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
