cf6e5d3c2d
commit 23a3b8d5a2365653fd9bc5a9454d1e7f4facbf85 upstream. Allow PCI hosts to check and tune roothub and port settings before the hub is up and running. This override is needed to turn off U1 and U2 LPM for some ports based on per port ACPI _DSM, _UPC, or possibly vendor specific mmio values for Intel xHC hosts. Usb core calls the host update_hub_device once it creates a hub. Entering U1 or U2 link power save state on ports with this limitation will cause link to fail, turning the usb device unusable in that setup. Cc: stable@vger.kernel.org Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20230116142216.1141605-5-mathias.nyman@linux.intel.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.