Re: [PATCH] x86/ioapic: Don't return 0 as valid virq

From: Borislav Petkov
Date: Sun Mar 12 2023 - 16:40:31 EST


On Thu, Mar 02, 2023 at 11:34:46AM -0800, Saurabh Sengar wrote:
> Zero is invalid virq and should't be returned as a valid value for
> lower irq bound. If IO-APIC and gsi_top are not initialized return

Why isn't gsi_top initialized?

What is this fixing?

Don't be afraid to do

git annotate arch/x86/kernel/apic/io_apic.c

and see which commit added this. This one:

3e5bedc2c258 ("x86/apic: Fix arch_dynirq_lower_bound() bug for DT enabled machines")

Now add the folks from this commit to Cc and tell them why in your case
gsi_top is not initialized and what they're breaking by doing that.

The more your commit message explains *why* you're fixing something, the
better it is for the maintainers/reviewers to actually know what to do.

Right now I'm reading this and I'm thinking, random, unjustified change.
Ignore.

Ok?

Thx.

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette