Manikanta Maddireddy
44c081db2a
Few endpoints like Wi-Fi supports power on/off and to leverage that root port must support hot-plug and hot-unplug. Tegra PCIe doesn't support hot-plug and hot-unplug, however it supports endpoint power on/off feature as follows, - Power off sequence: - Transition of PCIe link to L2 - Power off endpoint - Leave root port in power up state with the link in L2 - Power on sequence: - Power on endpoint - Apply hot reset to get PCIe link up PCIe client driver stops accessing PCIe endpoint config and BAR registers after endpoint is powered off. However, software applications like x11 server or lspci can access endpoint config registers in which case host controller raises "response decoding" errors. To avoid this scenario, add PCIe link up check in config read and write callback functions before accessing endpoint config registers. Change-Id: I47653cb0b580c2b764cb0ad9c42deeb9c8823c58 Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com> Reviewed-on: https://git-master.nvidia.com/r/c/linux-4.14/+/2371131 (cherry picked from commit be664bfdd901138222a8ea8bb17160a2fa9de04a) Reviewed-on: https://git-master.nvidia.com/r/c/linux-5.9/+/2407866 Reviewed-by: automaticguardword <automaticguardword@nvidia.com> Reviewed-by: Bitan Biswas <bbiswas@nvidia.com> Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com> Tested-by: mobile promotions <svcmobile_promotions@nvidia.com> GVS: Gerrit_Virtual_Submit
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 reStructuredText 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.