Re: [PATCH v4] cdx: add MSI support for CDX bus

[Gupta, Nipun]

Hi Greg,

On 10/5/2023 7:30 PM, Greg KH wrote:
> On Thu, Oct 05, 2023 at 03:46:34PM +0200, Thomas Gleixner wrote:
> > On Thu, Oct 05 2023 at 12:24, Greg KH wrote:
> > > > diff --git a/drivers/cdx/Kconfig b/drivers/cdx/Kconfig
> > > > index a08958485e31..86df7ccb76bb 100644
> > > > --- a/drivers/cdx/Kconfig
> > > > +++ b/drivers/cdx/Kconfig
> > > > @@ -8,6 +8,7 @@
> > > >   config CDX_BUS
> > > >   	bool "CDX Bus driver"
> > > >   	depends on OF && ARM64
> > > > +	select GENERIC_MSI_IRQ_DOMAIN
> > >
> > > This config option isn't in my tree anywhere, where did it come from?
> > > What is it supposed to do?
> >
> > 13e7accb81d6 ("genirq: Get rid of GENERIC_MSI_IRQ_DOMAIN") :)
>
> Ok, so this hasn't been tested since the 6.2 release?  Wow, I think
> someone from AMD needs to take a deep look at this and verify that it
> actually is doing what it is supposed to be doing...

The patch Thomas mentioned renames "GENERIC_MSI_IRQ_DOMAIN" to 
"GENERIC_MSI_IRQ"; and in our testing "GENERIC_MSI_IRQ" is also selected 
as 'ARM64' is enabled which enables 'ARM_GIC_V3_ITS' which in-turn 
selects 'GENERIC_MSI_IRQ'.

The patch is tested for MSI functionality on 6.6-rc1. We will re-look 
into the config dependencies to avoid such issues, but please be assured 
that the patch has been validated.

Thanks,
Nipun

> thanks,
>
> greg k-h