From: Huacai Chen <chenhc@lemote.com>
To: Marc Zyngier <maz@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
Thomas Gleixner <tglx@linutronix.de>,
Jason Cooper <jason@lakedaemon.net>,
"open list:MIPS" <linux-mips@vger.kernel.org>,
Fuxin Zhang <zhangfx@lemote.com>,
Jiaxun Yang <jiaxun.yang@flygoat.com>,
stable <stable@vger.kernel.org>
Subject: Re: [PATCH 3/3] irqchip/loongson-pch-pic: Reserve legacy LPC irqs
Date: Fri, 11 Sep 2020 18:12:55 +0800 [thread overview]
Message-ID: <CAAhV-H5-2SZOaGny68-PBP3_+afHk5XMuQRYgCQS50b_3fMj4A@mail.gmail.com> (raw)
In-Reply-To: <6af66ab3dbf81cc1d0cf4c204ebac2b8@kernel.org>
Hi, Marc,
On Fri, Sep 11, 2020 at 3:50 PM Marc Zyngier <maz@kernel.org> wrote:
>
> On 2020-09-11 05:13, Huacai Chen wrote:
> > Hi, Marc,
> >
> > On Thu, Sep 10, 2020 at 6:08 PM Marc Zyngier <maz@kernel.org> wrote:
> >>
> >> On 2020-09-09 05:09, Huacai Chen wrote:
> >> > Reserve legacy LPC irqs (0~15) to avoid spurious interrupts.
> >>
> >> How can they be spurious? Why are they enabled the first place?
> >>
> >> This looks like you are papering over a much bigger issue.
> > The spurious interrupts are probably occurred after kdump and the irq
> > number is in legacy LPC ranges. I think this is because the old kernel
> > doesn't (and it can't) disable devices properly so there are stale
> > interrupts in the kdump case.
>
> I don't really understand why the old kernel can't turn the interrupts
> off. Most architectures are able t, why not yours?
>
> Finally, why don't you just shut these interrupts off the first place
> in the interrupt controller init? Adding a whole lot of kernel
> data structures as a band-aid doesn't strike me as the best possible
> idea. Not to mention that if they keep firing, all you are doing
> is adding extra overhead.
After tests, I found that the previous patch (patch 2 in this series)
can avoid most spurious interrupts and kdump can work, so I will send
V2 to drop this patch.
Huacai
>
> M.
> --
> Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2020-09-11 10:13 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-09 4:09 [PATCH 1/3] MIPS: Loongson64: Increase NR_IRQS to 320 Huacai Chen
2020-09-09 4:09 ` [PATCH 2/3] irqchip/loongson-htvec: Fix initial interrupts clearing Huacai Chen
2020-09-09 4:09 ` [PATCH 3/3] irqchip/loongson-pch-pic: Reserve legacy LPC irqs Huacai Chen
2020-09-10 0:51 ` Jiaxun Yang
2020-09-10 1:40 ` Huacai Chen
2020-09-10 10:08 ` Marc Zyngier
2020-09-11 4:13 ` Huacai Chen
2020-09-11 7:50 ` Marc Zyngier
2020-09-11 10:12 ` Huacai Chen [this message]
2020-09-10 16:34 ` Sasha Levin
2020-09-11 0:12 ` Huacai Chen
2020-09-10 10:10 ` [PATCH 1/3] MIPS: Loongson64: Increase NR_IRQS to 320 Marc Zyngier
2020-09-11 3:24 ` Huacai Chen
2020-09-11 7:44 ` Marc Zyngier
2020-09-11 8:43 ` Huacai Chen
2020-09-11 9:03 ` Marc Zyngier
2020-09-11 9:14 ` Huacai Chen
2020-09-11 9:23 ` Marc Zyngier
2020-09-11 9:40 ` Huacai Chen
2020-09-10 16:34 ` Sasha Levin
2020-09-11 0:11 ` Huacai Chen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAAhV-H5-2SZOaGny68-PBP3_+afHk5XMuQRYgCQS50b_3fMj4A@mail.gmail.com \
--to=chenhc@lemote.com \
--cc=jason@lakedaemon.net \
--cc=jiaxun.yang@flygoat.com \
--cc=linux-mips@vger.kernel.org \
--cc=maz@kernel.org \
--cc=stable@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=tsbogend@alpha.franken.de \
--cc=zhangfx@lemote.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).