Re: [PATCH v8 00/10] PCI: qcom: Fix higher MSI vectors handling

[Johan Hovold <johan@kernel.org>]

On Fri, May 13, 2022 at 04:50:11PM +0300, Dmitry Baryshkov wrote:
> On 13/05/2022 15:52, Johan Hovold wrote:
> > On Fri, May 13, 2022 at 01:10:44PM +0300, Dmitry Baryshkov wrote:
> >> On Fri, 13 May 2022 at 12:36, Johan Hovold <johan@kernel.org> wrote:

> > Are you able to confirm that all sc8280xp systems have only four msi
> > IRQs?
> 
> Unfortunately no. I don't have access to the sc8280xp docs. Let's see if 
> BjornA can confirm this.

I just talked to Bjorn and he said they should be the same for all
sc8280xp, but of course there are complications like some of the
controllers actually having more than 4 interrupts (even if they may not
be usable).

Probably best to describe this in DT.
 
> > This seems like another case of using the kernel as a DT validator by
> > describing things in two places and making sure that they match.
> 
> Yep, this seems like a bad habit of mine: to distrust the DT.
> 
> > 
> > I assume the number of vectors will always be a multiple of the numbers
> > of msi IRQs. Right? Then we don't need to encode this number for every
> > supported platform in the corresponding PCIe driver even if we end up
> > describing it in the binding.
> 
> But it was your suggestion!

Heh. But with the caveat that I'd still prefer this to come from DT if
possible. :)

> Let's drop the warning then, parse what was passed by the DT and just 
> print the total amount of MSI IRQs.

Perfect, thanks!

Johan