[PATCH 1/3] PCI: designware: add legacy PCI interrupt mapping

[Lucas Stach]

Am Freitag, den 28.02.2014, 13:27 +0100 schrieb Arnd Bergmann:
> On Friday 28 February 2014 13:09:34 Lucas Stach wrote:
> > Am Freitag, den 28.02.2014, 12:37 +0100 schrieb Arnd Bergmann:
> > > On Friday 28 February 2014 12:27:36 Lucas Stach wrote:
> > > The interrupt-map doesn't even look well-formed, since it refers to
> > > a gic that has #interrupt-cells=<3>, but only has one cell with the
> > > value. This clearly cannot work at all. It should probably be
> > > 
> > >       interrupt-map = <0x0 0 &gic GIC_SPI 21 IRQ_TYPE_LEVEL_HIGH>;
> > > 
> > > Note that '53' is the IRQ number that is commonly assigned to
> > > SPI interrupt 21, since SPI starts at number 32 on GIC.
> > > 
> > Ah, I see. Thanks for the explanation. So we have a bogus Exynos DT,
> > which will break existing systems once the kernel starts to do the right
> > thing. This is starting to look great. 
>  
> It seems tegra and r-car have the same bug. We can probably fix it
> in a backwards-compatible way by changing the function to call
> the generic helper first and if that fails call printk_once()
> to emit a warning and return the hardwired IRQ number.
> 

Yes, seems like the way to go. I'll prepare some patches for that. It
seems of_irq_parse_and_map_pci() already emits an error message if it
can't find a valid mapping. This should be enough to get people to fix
their DTs.

Regards,
Lucas 

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