Messages in this thread | | | Subject | Re: [PATCH] irqchip/sifive-plic: drop quirk for two-cell variant | From | Icenowy Zheng <> | Date | Wed, 23 Nov 2022 20:38:56 +0800 |
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在 2022-11-22星期二的 17:28 +0000,Marc Zyngier写道: > On Mon, 21 Nov 2022 04:20:26 +0000, > Icenowy Zheng <uwu@icenowy.me> wrote: > > > > As the special handling of edge-triggered interrupts are defined in > > the > > PLIC spec, we can assume it's not a quirk, but a feature of the > > PLIC > > spec; thus making it a quirk and use quirk-based codepath is not so > > necessary. > > It *is* necessary. > > > > > Move to a #interrupt-cells-based practice which will allow both > > device > > trees without interrupt flags and with interrupt flags work for all > > compatible strings. > > No. You're tying together two unrelated concepts: > > - Edges get dropped in some implementations (and only some). You can > argue that the architecture allows it, but I see it is an > implementation bug.
As the specification allows it, it's not an implementation bug -- and for those which do not show this problem, it's possible that it's just all using the same trigger type (e.g. Rocket).
> > - The need for expressing additional information in the interrupt > specifier is not necessarily related to the above. Other interrupt > controllers use extra cells to encode the interrupt affinity, for > example.
I think in these situations, if the interrupt controller does not contain any special handling for edge interrupts, we can just describe them as level ones in SW.
> > I want these two things to be kept separate. Otherwise, once we get > some fancy ACPI support for RISCV (no, please...), we'll have to redo > the whole thing... > > > In addition, this addresses a stable version DT binding violation - > > - > > Linux v5.19 comes with "thead,c900-plic" with #interrupt-cells > > defined to > > be 1 instead of 2, this commit will allow DTs that complies to > > Linux > > v5.19 binding work (although no such DT is devliered to the public > > now). > > *That* is what should get fixed.
Supporting all stable versions' DT binding is our promise, I think.
> > Thanks, > > M. >
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