[PATCH] riscv: hwprobe: require both F and D extensions for RISCV_HWPROBE_IMA_FD

[Ivy Lopez]

On Mon, Aug 17, 2026 at 03:14:36PM +0100, Conor Dooley wrote:
> The kernel never supports F without D, so this cannot occur.
> riscv_isa_extension_available(NULL, f) always returns false if D is not
> also present.
>
> If anything, the code in has_fpu() should be changed to only check D and
> not F to match expectations elsewhere, or F and D for the same reason.

Ah ok, thanks for the clarification.. I hadn't realized F-without-D is
already structurally impossible here, so this patch doesn't change
actual behavior.

Would you prefer a v2 that fixes has_fpu() instead (checking D only,
or F && D, whichever matches the intended semantics elsewhere), or
would you rather I just drop this patch since RISCV_HWPROBE_IMA_FD already
behaves correctly in practice?

Happy to send whichever you'd find useful!