]> git.baikalelectronics.ru Git - kernel.git/commit
xhci: USB 3.0 BW checking.
authorSarah Sharp <sarah.a.sharp@linux.intel.com>
Tue, 13 Sep 2011 23:41:13 +0000 (16:41 -0700)
committerGreg Kroah-Hartman <gregkh@suse.de>
Tue, 20 Sep 2011 19:33:50 +0000 (12:33 -0700)
commitd3f2142a4a4397f4fb1f5bfa0190d7b44718c2bf
treefd857f901beaf7c60b7015422aa5bc85e4a8eebe
parentce10d7095237fa237e8dbcf68f4c1c59f35fc6f7
xhci: USB 3.0 BW checking.

The Intel Panther Point xHCI host tracks SuperSpeed endpoints in a
different way than USB 2.0/1.1 endpoints.  The bandwidth interval tables
are not used, and instead the bandwidth is calculated in a very simple
way.  Bandwidth for SuperSpeed endpoints is tracked individually in each
direction, since each direction has the full USB 3.0 bandwidth available.
10% of the bus bandwidth is reserved for non-periodic transfers.

This checking would be more complex if we had USB 3.0 LPM enabled, because
an additional latency for isochronous ping times need to be taken into
account.  However, we don't have USB 3.0 LPM support in Linux yet.

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