Re: [PATCH 2/3] ARM: dts: bcm2711: Update SPI nodes compatible strings

[Lukas Wunner]

On Thu, Jun 04, 2020 at 12:13:25PM +0100, Mark Brown wrote:
> On Thu, Jun 04, 2020 at 06:20:38AM +0200, Lukas Wunner wrote:
> > On Wed, Jun 03, 2020 at 08:46:54PM -0700, Florian Fainelli wrote:
> > > The BCM2711 SoC features 5 SPI controllers which all share the same
> > > interrupt line, the SPI driver needs to support interrupt sharing,
> > > therefore use the chip specific compatible string to help with that.
> 
> > You're saying above that the 5 controllers all share the interrupt
> > but below you're only changing the compatible string of 4 controllers.
> 
> > So I assume spi0 still has its own interrupt and only the additional
> > 4 controllers present on the BCM2711/BCM7211 share their interrupt?
> 
> Regardless of what's going on with the interrupts the compatible string
> should reflect the IP version so unless for some reason someone taped
> out two different versions of the IP it seems odd that the compatible
> strings would vary within a given SoC.

Hm.  I guess it may be possible to search the DT for other devices
sharing the same interrupt line and thereby determine whether
IRQF_SHARED is necessary.  The helper to perform this search could
live in drivers/of/irq.c as I imagine it might be useful in general.