On Thu, Dec 02, 2021 at 04:06:21PM +0100, Geert Uytterhoeven wrote:
> Hi Marc,
>
> On Wed, Dec 1, 2021 at 12:41 PM Marc Zyngier <maz@xxxxxxxxxx> wrote:
> > Since 041284181226 ("of/irq: Allow matching of an interrupt-map local
> > to an interrupt controller"), a handful of interrupt controllers have
> > stopped working correctly. This is due to the DT exposing a non-sensical
> > interrupt-map property, and their drivers relying on the kernel ignoring
> > this property.
> >
> > Since we cannot realistically fix this terrible behaviour, add a quirk
> > for the limited set of devices that have implemented this monster,
> > and document that this is a pretty bad practice.
> >
> > Cc: Rob Herring <robh@xxxxxxxxxx>
> > Cc: John Crispin <john@xxxxxxxxxxx>
> > Cc: Biwen Li <biwen.li@xxxxxxx>
> > Cc: Chris Brandt <chris.brandt@xxxxxxxxxxx>
> > Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> > Cc: Sander Vanheule <sander@xxxxxxxxxxxxx>
> > Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> > ---
> >
> > Notes:
> > v2: Switched over to of_device_compatible_match() as per Rob's
> > request.
>
> Thanks for the update!
>
> > --- a/drivers/of/irq.c
> > +++ b/drivers/of/irq.c
>
> > @@ -159,12 +179,16 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
> > /*
> > * Now check if cursor is an interrupt-controller and
> > * if it is then we are done, unless there is an
> > - * interrupt-map which takes precedence.
> > + * interrupt-map which takes precedence if we're not
> > + * in presence of once of these broken platform that
>
> one
and 'platforms'. Will fixup.
>
> > + * want to parse interrupt-map themselves for $reason.
> > */
> > bool intc = of_property_read_bool(ipar, "interrupt-controller");
> > + bool imap_abuse;
> >
> > imap = of_get_property(ipar, "interrupt-map", &imaplen);
> > - if (imap == NULL && intc) {
> > + imap_abuse = imap && of_device_compatible_match(ipar, of_irq_imap_abusers);
>
> ... = intc && imap && of_device_compatible_match(...)
Why? Then we are comparing intc twice because we still need it for the
intc && !imap case.
>
> > + if (intc && (imap == NULL || imap_abuse)) {
> > pr_debug(" -> got it !\n");
> > return 0;
> > }
>
> Still working fine on RZ/A1, so
> Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
>
