3d394fa375
[ Upstream commit 91a8d79fc797d3486ae978beebdfc55261c7d65b ] It looks like that mvebu PCIe controller has for each PCIe link fully independent PCIe host bridge and so every PCIe Root Port is isolated not only on its own bus but also isolated from each others. But in past device tree structure was defined to put all PCIe Root Ports (as PCI Bridge devices) into one root bus 0 and this bus is emulated by pci-mvebu.c driver. Probably reason for this decision was incorrect understanding of PCIe topology of these Armada SoCs and also reason of misunderstanding how is PCIe controller generating Type 0 and Type 1 config requests (it is fully different compared to other drivers). Probably incorrect setup leaded to very surprised things like having PCIe Root Port (PCI Bridge device, with even incorrect Device Class set to Memory Controller) and the PCIe device behind the Root Port on the same PCI bus, which obviously was needed to somehow hack (as these two devices cannot be in reality on the same bus). Properly set mvebu local bus number and mvebu local device number based on PCI Bridge secondary bus number configuration. Also correctly report configured secondary bus number in config space. And explain in driver comment why this setup is correct. Link: https://lore.kernel.org/r/20211125124605.25915-12-pali@kernel.org Fixes: 1f08673eef12 ("PCI: mvebu: Convert to PCI emulated bridge config space") Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.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.