USB: xhci: Scatter gather list support for bulk transfers.
commit8a96c052283e68fe91a6c657c175b39bfed80bed
authorSarah Sharp <sarah.a.sharp@linux.intel.com>
Tue, 28 Apr 2009 02:59:19 +0000 (27 19:59 -0700)
committerGreg Kroah-Hartman <gregkh@suse.de>
Tue, 16 Jun 2009 04:44:49 +0000 (15 21:44 -0700)
treecf32b4462b2f3f59554b3531d866b60be2c4f6a1
parente04748e3a87271fcf30d383e3780c5d3ee1c1618
USB: xhci: Scatter gather list support for bulk transfers.

Add support for bulk URBs that pass scatter gather lists to xHCI.  This allows
xHCI to more efficiently enqueue these transfers, and allows the host
controller to take advantage of USB 3.0 "bursts" for bulk endpoints.

Use requested length to calculate the number of TRBs needed for a scatter gather
list transfer, instead of using the number of sglist entries.  The application
can pass down a scatter gather list that is bigger than it needs for the
requested transfer.

Scatter gather entries can cross 64KB boundaries, so be careful to setup TRBs
such that no buffer crosses a 64KB boundary.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/host/xhci-ring.c