Triode wrote: > Great - let us know where you get to. My only waryness with this is > that we don't want to get into needing to look at linux usb drivers, so > I would prefer to be using the ones commonly used and know to be > working. The Pi uses something which appears not to have a hardware > scheduler and relies on the interrupt driver to schedule packets - which > leads to it missing packets in iso streams... The EHCI principle of > having a hardware schedule is working well for us on other devices so is > lowest risk... (Plus I spend too long instrumenting the EHCI scheduler > to reach the conclusion of what Touch hardware would do :))
I found out that the recent kernels have a config option that lets you choose whether you want to use musb or ehci with the TI processors. Since the BeagleBone uses one port in host mode and one in device mode it has to enable the musb driver. Once I get mine in I'm going to try compiling the kernel with just the ehci driver and see if that works. The config also has two TT modes so I can try those out and see if they make any difference. The problem people seem to have happening is that the musb implementation of the DMA subsystem is not working, forcing them to switch to PIO mode, which when the processor gets busy causes problems. (it seems to be fine as long as the processor is not busy) I have also seen messages of a patch designed to fix the DMA issue with the musb, so the issue may be fixed already. So it looks like we will not need to hack the driver code, just make sure we use the RIGHT one. I'll let you know if I'm having any problems with figuring out the correct config settings. John S. ------------------------------------------------------------------------ JohnSwenson's Profile: http://forums.slimdevices.com/member.php?userid=5974 View this thread: http://forums.slimdevices.com/showthread.php?t=97881 _______________________________________________ discuss mailing list discuss@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/discuss
