Hi, I think there are a few bits to put the high 32-bits into the transfer descriptors and such missing. You are right we don`t really need to use 32-bit only for the USB controllers. Though we`ve seen a couple of times that even 32-bit controllers don`t implement the full 32-address lines. Typically 2GB limits are found.
--HPS -----Original message----- > From:aseem.jolly <aseem.jo...@gmail.com <mailto:aseem.jo...@gmail.com> > > Sent: Saturday 3rd August 2013 2:17 > To: freebsd-usb@freebsd.org <mailto:freebsd-usb@freebsd.org> > Subject: USB DMA memory Allocation > > It seems to me that Intel ehci controller supports 64 DMA address lines > (HCCPARAMS register's 0 bit is set hardwired) then why do force DMA > allocation from [0 4GB] range. > > I tried to enable 64 bit DMA allocations by modifying call to > 'usb_dma_tag_setup' in usb_controller.c and usb_transfer.c but got a device > disconnect after we preallocated DMA memory for USB transfers. > > Would be really great if someone could guide me on this. > > > > > -- > View this message in context: > http://freebsd.1045724.n5.nabble.com/USB-DMA-memory-Allocation-tp5833506.html > <http://freebsd.1045724.n5.nabble.com/USB-DMA-memory-Allocation-tp5833506.html> > > Sent from the freebsd-usb mailing list archive at Nabble.com. > _______________________________________________ > freebsd-usb@freebsd.org <mailto:freebsd-usb@freebsd.org> mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-usb > <http://lists.freebsd.org/mailman/listinfo/freebsd-usb> > To unsubscribe, send any mail to "freebsd-usb-unsubscr...@freebsd.org > <mailto:freebsd-usb-unsubscr...@freebsd.org> " > _______________________________________________ freebsd-usb@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-usb To unsubscribe, send any mail to "freebsd-usb-unsubscr...@freebsd.org"
