lkml.org 
[lkml]   [2014]   [Oct]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] x86: Fix XT-PIC-XT-PIC in /proc/interrupts

* Maciej W. Rozycki <macro@linux-mips.org> wrote:

> On Mon, 27 Oct 2014, Ingo Molnar wrote:
>
> > What's the effect of this change on the output for non-8259A irq
> > controllers?
>
> Good question, I didn't expect any other IRQ controller to be used for
> ISA interrupts (the APIC is handled elsewhere). I have checked the
> sources and the only other controller that can be used for `legacy_pic'
> is `dummy_irq_chip' (cf. `default_legacy_pic' vs `null_legacy_pic' in
> arch/x86/kernel/i8259.c). That affects `init_ISA_irqs' only (the other
> place, `make_8259A_irq', has a reference to `i8259A_chip' hardcoded).
>
> In this case the output would change from "dummy-dummy" to "dummy",
> which IMHO has just as much value as the change from "XT-PIC-XT-PIC" to
> "XT-PIC". However I don't think you'd be able to request such IRQs so
> they will never show up in /proc/interrupts, making this observation
> largely irrelevant. If you think I may be wrong here, then can you
> please find such a system and try this change with it (or can someone
> else reading this make this check for me by any chance)? Unfortunately
> all x86 hardware I have does have an 8259A pair.
>
> Also please note that both places explicitly refer to the name of the
> IRQ chip being installed as the name of the handler as well, with
> `i8259A_chip.name' and `chip->name' respectively, this is hardcoded.
> So no matter which chip is used there'll be a duplicate name in
> /proc/interrupts.
>
> Does this answer address your concern?

Yeah, it addresses it, I'll queue up your fix, thanks!

Ingo


\
 
 \ /
  Last update: 2014-10-27 14:21    [W:0.136 / U:0.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site