svn commit: r213931 - head/sys/dev/usb/storage

[Alexander Motin]

Author: mav
Date: Sat Oct 16 19:29:37 2010
New Revision: 213931
URL: http://svn.freebsd.org/changeset/base/213931

Log:
  Allow umass to use bigger transactions for USB 3.0 devices. It is less
  important for USB 2.0 devices and some of them reported to have problems
  with large transactions. But USB 3.0 benchmarks show that limited number
  of transactions per second on USB makes impossible to reach high transfer
  speeds without using bigger transactions.
  
  On my tests this change allows to read up to 220MB/s from USB-attached SSD
  (at block size of 256-512KB), comparing to only 113MB/s without it.
  
  Reviewed by:	hselasky

Modified:
  head/sys/dev/usb/storage/umass.c

Modified: head/sys/dev/usb/storage/umass.c
==============================================================================
--- head/sys/dev/usb/storage/umass.c	Sat Oct 16 19:25:27 2010	(r213930)
+++ head/sys/dev/usb/storage/umass.c	Sat Oct 16 19:29:37 2010	(r213931)
@@ -2418,6 +2418,7 @@ umass_cam_action(struct cam_sim *sim, un
 					case USB_SPEED_SUPER:
 						cpi->base_transfer_speed =
 						    UMASS_SUPER_TRANSFER_SPEED;
+						cpi->maxio = MAXPHYS;
 						break;
 					case USB_SPEED_HIGH:
 						cpi->base_transfer_speed =