On Fri, 09 Sep 2022 15:52:45 +0100, Frank Li <frank.li@xxxxxxx> wrote: > > > > + select IRQ_DOMAIN > > > + select IRQ_DOMAIN_HIERARCHY > > > + select GENERIC_MSI_IRQ_DOMAIN > > > + help > > > + MU work as MSI controller to do general doorbell > > > > I'm not sure this is that generic. It really is limited to CPU-to-CPU > > interrupts. > > [Frank Li] I think the only limitation is only 4 irq numbers. > The principle CPU to CPU irq is the same as MSI. Not quite. Normal MSIs are device-to-CPU. CPU-to-CPU are normally IPIs, and this one falls in the middle. > What's your preferred help description? <quote> Provide a driver for the MU block used as a CPU-to-CPU MSI controller. This requires a specially crafted DT to make use of this driver. If unsure, say N. </quote> M. -- Without deviation from the norm, progress is not possible.
