666f3de741
Synopsys introduced a new enhancement to DWC_usb32 called Multi-Stream Transfer (MST) to improve bulk streams performance for SuperSpeed and SuperSpeed Plus. This enhancement allows the controller to look ahead and process multiple bulk streams. Previously, to initiate a bulk stream transfer, the driver has to issue Start Transfer command and wait for the stream to complete before initiating a new stream. As a result, the controller does not process TRBs beyond a single stream. With the enhancement, as long as there are new requests, the dwc3 driver can keep preparing new TRBs and the controller can keep caching and processing them without waiting for the transfer completion. The programming flow is similar to regular bulk endpoint with a few additional rules: 1) Chained TRBs of the same stream must have a matching stream ID 2) The last TRB of a stream must have CHN=0 3) All the TRBs with LST=0 must have CSP=1 Depends on the application and usage, internal tests show significant performance improvement in UASP transfers with this enhancement. Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com> Link: https://lore.kernel.org/r/cd9c7a8bf11f790983ac546222dd114893f16b3a.1638242424.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.