On Thu, Feb 20, 2020 at 11:29:28AM -0800, Sean V Kelley wrote: > Changes since v1 [1]: > > - Correct Documentation section title for 6300ESB chipset. > (Jonathan Derrick) > > - Use consistent abbreviations in comments for IO-APIC and Core IO. > (Andy Shevchenko) > > - Retained Reviewed-by tag due to no technical changes. > > [1]: https://lore.kernel.org/lkml/20200214213313.66622-1-sean.v.kelley@xxxxxxxxxxxxxxx/ > > Bjorn, I'm open for it to go to stable as well. > > -- > > When IRQ lines on secondary or higher IO-APICs are masked (e.g., > Real-Time threaded interrupts), many chipsets redirect IRQs on > this line to the legacy PCH and in turn the base IO-APIC in the > system. The unhandled interrupts on the base IO-APIC will be > identified by the Linux kernel as Spurious Interrupts and can > lead to disabled IRQ lines. > > Disabling this legacy PCI interrupt routing is chipset-specific and > varies in mechanism between chipset vendors and across generations. > In some cases the mechanism is exposed to BIOS but not all BIOS > vendors chose to pick it up. With the increasing usage of RT as it > marches towards mainline, additional issues have been raised with > more recent Xeon chipsets. > > This patchset disables the boot interrupt on these Xeon chipsets where > this is possible with an additional mechanism. In addition, this > patchset includes documentation covering the background of this quirk. > > > Sean V Kelley (2): > pci: Add boot interrupt quirk mechanism for Xeon chipsets > Documentation:PCI: Add background on Boot Interrupts > > Documentation/PCI/boot-interrupts.rst | 153 ++++++++++++++++++++++++++ > Documentation/PCI/index.rst | 1 + > drivers/pci/quirks.c | 80 ++++++++++++-- > 3 files changed, 227 insertions(+), 7 deletions(-) > create mode 100644 Documentation/PCI/boot-interrupts.rst Applied to pci/interrupts for v5.7. I added a stable tag. Thanks a lot; this is really a nice piece of work!
