]> 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)
commit63f86c23a12521d8a14a4e2c968f361a707e2919
treefd857f901beaf7c60b7015422aa5bc85e4a8eebe
parentdcdd3485a54dfb0ec312917320c6fc668ba60a31
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