On Monday 02 July 2007, Leyden, Mark wrote: > Hi, > > I'm having problems with an NEC EHCI host controller on a Linux based > embedded system. We're currently using version 2.4.32 of the kernel but > have included the USB changes made to the 2.4.34 kernel.
So I take it you can't try to reproduce this with 2.6.current? The Linux 2.4 EHCI code is quite ancient, and has various bugs that have been fixed in current kernels. I can't even remember the last time a bugfix went into that code. > From the traces we have observed, it would appear that the host > controller is failing to overlay the QTD into the respective QH's > overlay area. There were a number of finickey behaviors in that area in the older EHCI code. You might look at the qh_completions() logic and the code which adds TDs to a QH, comparing to 2.6.current; there are various little dodgey races when reading and writing the live TD lists, and it's very possible your embedded system has timings that create trouble... I recall there are some cases where various EHCI 0.95 implementations had surprising behavior. Usually it was at the level of overlaying something that shouldn't have been overlaid, but there were a few other oddities too. - Dave ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
