summaryrefslogtreecommitdiffstats
path: root/Documentation/usb/bulk-streams.txt
Commit message (Collapse)AuthorAgeFilesLines
* USB: Support for allocating USB 3.0 streams.Sarah Sharp2010-05-201-0/+78
Bulk endpoint streams were added in the USB 3.0 specification. Streams allow a device driver to overload a bulk endpoint so that multiple transfers can be queued at once. The device then decides which transfer it wants to work on first, and can queue part of a transfer before it switches to a new stream. All this switching is invisible to the device driver, which just gets a completion for the URB. Drivers that use streams must be able to handle URBs completing in a different order than they were submitted to the endpoint. This requires adding new API to set up xHCI data structures to support multiple queues ("stream rings") per endpoint. Drivers will allocate a number of stream IDs before enqueueing URBs to the bulk endpoints of the device, and free the stream IDs in their disconnect function. See Documentation/usb/bulk-streams.txt for details. The new mass storage device class, USB Attached SCSI Protocol (UASP), uses these streams API. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>