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commit8e98b69700upstream. pci_fixup_irqs() used to call pcibios_map_irq on every PCI device, which for RT2880 included bus 0 slot 0. After pci_fixup_irqs() got removed, only slots/funcs with devices attached would be called. While arguably the right thing, that left no chance for this driver to ever initialize slot 0, effectively bricking PCI and USB on RT2880 devices such as the Belkin F5D8235-4 v1. Slot 0 configuration needs to happen after PCI bus enumeration, but before any device at slot 0x11 (func 0 or 1) is talked to. That was determined empirically by testing on a Belkin F5D8235-4 v1 device. A minimal BAR 0 config write followed by read, then setting slot 0 PCI_COMMAND to MASTER | IO | MEMORY is all that seems to be required for proper functionality. Tested by ensuring that full- and high-speed USB devices get enumerated on the Belkin F5D8235-4 v1 (with an out of tree DTS file from OpenWrt). Fixes:04c81c7293("MIPS: PCI: Replace pci_fixup_irqs() call with host bridge IRQ mapping hooks") Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Tobias Wolf <dev-NTEO@vplace.de> Cc: <stable@vger.kernel.org> # v4.14+ Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> 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.