svn commit: r279563 - head/sys/dev/usb/controller

[Marius Strobl]

On Tue, Mar 03, 2015 at 10:21:55AM +0000, Hans Petter Selasky wrote:
> Author: hselasky
> Date: Tue Mar  3 10:21:54 2015
> New Revision: 279563
> URL: https://svnweb.freebsd.org/changeset/base/279563
> 
> Log:
>   Add quirk for USB 3.0 controllers which don't support 64-bit DMA.
>   

Hrm, this is strange; I checked Linux sources when adding 64-bit DMA
support and while they handle tons of quirks for USB controllers
(which FreeBSD doesn't), they don't have a single such exception for
64-bit DMA. Are you sure using 64-bit DMA doesn't just reveal another
problem? F. e., Linux issues an extra doorbell ring for XHCI_NEC_HOST
and generally reads back the doorbell register in order to flush PCI
writes.

Marius