Re: [PATCH v2 10/10] RISC-V: provide a Kconfig option to disable parsing "riscv,isa"

From: Andrew Jones
Date: Fri Jun 30 2023 - 03:48:06 EST


On Thu, Jun 29, 2023 at 10:44:18PM +0100, Conor Dooley wrote:
> On Thu, Jun 29, 2023 at 02:16:49PM -0700, Palmer Dabbelt wrote:
> > On Thu, 29 Jun 2023 13:20:55 PDT (-0700), Conor Dooley wrote:
...
> > > +bool __initdata riscv_isa_fallback_cmdline = false;
> > > +static int __init riscv_isa_fallback_setup(char *__unused)
> >
> > Maybe it's better to support =true and =false here? Not sure it matters,
> > we're already down a rabbit hole ;)
>
> Dunno, not implemented a cmdline param before. Seemed "cleaner" to check
> for presence, don't really care so I'll adapt to w/e.
>

I don't have a strong preference here, but to throw in more food for
thought, I see this DT-v1 vs. DT-v2 choice to be a bit analogous to the
DT vs. ACPI choice. The 'acpi' command line parameter, for RISC-V, can
be 'off', 'on', and 'force', where

off -- disable ACPI if default was on
on -- enable ACPI but allow fallback to DT
force -- enable ACPI if default was off

So, if the default of the isa fallback command line option will depend on
Kconfig, then we may also want a 'force'.

Thanks,
drew