719e1f561a
The platform _OSC can change the hardware state when query bit is not set. According to ACPI spec it is recommended that the OS runs _OSC with query bit set until the platform does not mask any of the capabilities. Then it should run it with query bit clear in order to actually commit the changes. Linux has not been doing this for the reasons that there has not been anything to commit, until now. The ACPI 6.4 introduced _OSC for USB4 to allow the OS to negotiate native control over USB4 tunneling. The platform might implement this so that it only activates the software connection manager path when the OS calls the _OSC with the query bit clear. Otherwise it may default to the firmware connection manager, for instance. For this reason modify the _OSC support so that we first execute it with query bit set, then use the returned value as base of the features we want to control and run the _OSC again with query bit clear. This also follows what Windows is doing. Also rename the function to better match what it does. Signed-off-by: Mario Limonciello <mario.limonciello@dell.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> |
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.