b516ea586d
Many NVIDIA GPUs can be configured as either a single-function video device or a multi-function device with video at function 0 and an HDA audio controller at function 1. The HDA controller can be enabled or disabled by a bit in the function 0 config space. Some BIOSes leave the HDA disabled, which means the HDMI connector from the NVIDIA GPU may not work. Sometimes the BIOS enables the HDA if an HDMI cable is connected at boot time, but that doesn't handle hotplug cases. Enable the HDA controller on device enumeration and resume and re-read the header type, which tells us whether the GPU is a multi-function device. This quirk is limited to NVIDIA PCI devices with the VGA Controller device class. This is expected to correspond to product configurations where the NVIDIA GPU has connectors attached. Other products where the device class is 3D Controller are expected to correspond to configurations where the NVIDIA GPU is dedicated (dGPU) and has no connectors. See original post (URL below) for more details. This commit takes inspiration from an earlier patch by Daniel Drake. Link: https://lore.kernel.org/r/20190708051744.24039-1-drake@endlessm.com v2 Link: https://lore.kernel.org/r/20190613063514.15317-1-drake@endlessm.com v1 Link: https://devtalk.nvidia.com/default/topic/1024022 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75985 Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Daniel Drake <drake@endlessm.com> [bhelgaas: commit log, log message, return early if already enabled] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Aaron Plattner <aplattner@nvidia.com> Cc: Peter Wu <peter@lekensteyn.nl> Cc: Ilia Mirkin <imirkin@alum.mit.edu> Cc: Karol Herbst <kherbst@redhat.com> Cc: Maik Freudenberg <hhfeuer@gmx.de> |
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| fs | ||
| include | ||
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| kernel | ||
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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.