Hi Kallol, On Tue, Feb 13, 2018 at 10:21:04AM -0800, Kallol Biswas wrote: > Hi Bjorn, > I am facing an interrupt generation issue when single MSI > is shared by both dpc and hotplug interrupt. > > The DS port is multi-MSI capable. What I have noticed that if I move > the switch (with DS port) and OS disk to a different system multiple > MSI vectors are allocated and dpc isr and hotplug isr are on different > vectors. > > It seems that BIOS controls allocation of MSI vectors. Is there anyway > to force linux kernel to allocate multiple vectors when port is > capable? BIOS doesn't control the allocation of MSI vectors. That's done by Linux in pcie_init_service_irqs(), and it depends on many things: what services are supported by Linux (hotplug, PME, AER, DPC), which ones Linux is allowed to use (based on the ACPI _OSC method, so this part can be influenced by the BIOS), etc. If you can share the "lspci -vv" and dmesg output for these two systems, we can probably work out what's going on. Things should *work* even if DPC and hotplug need to share an interrupt. If that doesn't work, that's a Linux bug that should be fixed. Bjorn
