Re: [PATCH v3] sh: avoid using IRQ0 on SH3/4
From: Maciej W. Rozycki
Date: Tue May 03 2022 - 15:46:51 EST
On Tue, 3 May 2022, Geert Uytterhoeven wrote:
> > Sounds like it's now outside of the IRQ range allocation, but I can't find where
> > that's requested when registering the controller? (What is a "swizzle" anyway?)
>
> PCI slots have 4 interrupts (#A, #B, #C, #D). In machines with
> multiple slots, the interrupts lines are "swizzled", to avoid that all cards
> using a single interrupt are mapped to the same host interrupt.
Especially as single-function devices are required to use INTA.
Maciej