Re: [PATCH v2] arm64/fpsimd: Only provide the length to cpufeature for xCR registers

From: Catalin Marinas
Date: Wed Aug 09 2023 - 12:11:46 EST


On Fri, Aug 04, 2023 at 05:37:25PM +0100, Mark Brown wrote:
> On Fri, Aug 04, 2023 at 05:20:21PM +0100, Catalin Marinas wrote:
> > On Thu, Aug 03, 2023 at 06:44:24PM +0100, Mark Brown wrote:
> > > On Thu, Aug 03, 2023 at 05:39:38PM +0100, Catalin Marinas wrote:
> > > > Maybe that's the simplest fix, especially if you want it in stable, but
> > >
> > > Yeah, it's definitely the sort of change we want as a fix - anything
> > > more invasive would be inappropriate.
> >
> > I'd say it's still ok if we can just rip come code out safely (the fake
> > ID reg).
>
> It's the safely bit that concerns me here - it feels like a great way to
> discover why the code was there, possibly including a use that was there
> in the past but has subsequently been removed so bites a stable version.

As discussed earlier, let's queue this patch as is (for 6.6 I'd say)
with cc stable and post a new patch on top that removes the fake CPUID
register going forward, in case we missed anything.

For this patch:

Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>