Hi Jisheng, On 29/09/2020 11:48, Jisheng Zhang wrote: > Hi Jon, > > On Fri, 25 Sep 2020 09:53:45 +0100 Jon Hunter wrote: > >> >> On 24/09/2020 12:05, Jisheng Zhang wrote: >>> Improve the msi code: >>> 1. Add proper error handling. >>> 2. Move dw_pcie_msi_init() from each users to designware host to solve >>> msi page leakage in resume path. >> >> Apologies if this is slightly off topic, but I have been meaning to ask >> about MSIs and PCI. On Tegra194 which uses the DWC PCI driver, whenever we >> hotplug CPUs we see the following warnings ... >> >> [ 79.068351] WARNING KERN IRQ70: set affinity failed(-22). >> [ 79.068362] WARNING KERN IRQ71: set affinity failed(-22). >> > > I tried to reproduce this issue on Synaptics SoC, but can't reproduce it. > Per my understanding of the code in kernel/irq/cpuhotplug.c, this warning > happened when we migrate irqs away from the offline cpu, this implicitly > implies that before this point the irq has bind to the offline cpu, but how > could this happen given current dw_pci_msi_set_affinity() implementation > always return -EINVAL By default the smp_affinity should be set so that all CPUs can be interrupted ... $ cat /proc/irq/70/smp_affinity 0xff In my case there are 8 CPUs and so 0xff implies that the interrupt can be triggered on any of the 8 CPUs. Do you see the set_affinity callback being called for the DWC irqchip in migrate_one_irq()? Cheers Jon -- nvpublic
