On Sunday 27 May 2007 22:54, M. Warner Losh wrote: > In message: <[EMAIL PROTECTED]> > > Hans Petter Selasky <[EMAIL PROTECTED]> writes: > : I've got some reports back that some USB host controllers do not support > : transferring memory from a location higher than 2GB. > : > : What should we do about this? > : > : Should we limit all USB DMA allocations to the lower 2GB of the memory? > > busdma should be managing this behind the scenes. You shouldn't care, > as the problematical usb controllers, if any, can do the bouncing as > required. We need to get the hierarchical bus tagging stuff more > fully integrated, then we'd get this for free.
Yes, I just changed the lowaddr when I allocated the tag, and that did the trick! > > Of course, you'd have to stop using contigmalloc to allocate all the > memory for usb. That won't work on some of the embedded platforms we > have, for example, because memory on them isn't as fungible as it is > on i386 and amd64. My new USB stack has been using "bus_dmamem" for quite a while. --HPS _______________________________________________ freebsd-usb@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-usb To unsubscribe, send any mail to "[EMAIL PROTECTED]"
