Ilya Lipnitskiy
c9e89ffa7a
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 ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.