On Jun 11, 2010, at 10:37 AM, Scott Long wrote: > > I'm not clear why you even need bounce buffers for RX. The chip supports > 64bit addresses with no boundary or alignment restrictions.
As per: /* * All controllers that are not 5755 or higher have 4GB * boundary DMA bug. * Whenever an address crosses a multiple of the 4GB boundary * (including 4GB, 8Gb, 12Gb, etc.) and makes the transition * from 0xX_FFFF_FFFF to 0x(X+1)_0000_0000 an internal DMA * state machine will lockup and cause the device to hang. */ if (BGE_IS_5755_PLUS(sc) == 0) sc->bge_flags |= BGE_FLAG_4G_BNDRY_BUG; and: lowaddr = BUS_SPACE_MAXADDR; if ((sc->bge_flags & BGE_FLAG_40BIT_BUG) != 0) lowaddr = BGE_DMA_MAXADDR; if ((sc->bge_flags & BGE_FLAG_4G_BNDRY_BUG) != 0) lowaddr = BUS_SPACE_MAXADDR_32BIT; /* * Allocate the parent bus DMA tag appropriate for PCI. */ error = bus_dma_tag_create(bus_get_dma_tag(sc->bge_dev), 1, 0, lowaddr, BUS_SPACE_MAXADDR, NULL, NULL, BUS_SPACE_MAXSIZE_32BIT, 0, BUS_SPACE_MAXSIZE_32BIT, 0, NULL, NULL, &sc->bge_cdata.bge_parent_tag); -- Marcel Moolenaar xcl...@mac.com _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"