From: Bjorn Helgaas <bjorn.helgaas@hp.com>
To: Olaf Dabrunz <od@suse.de>
Cc: Stefan Assmann <sassmann@suse.de>,
Shaohua Li <shaohua.li@intel.com>, Len Brown <lenb@kernel.org>,
Ingo Molnar <mingo@elte.hu>,
Jesse Barnes <jbarnes@virtuousgeek.org>,
Thomas Gleixner <tglx@linutronix.de>,
Steven Rostedt <rostedt@goodmis.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>,
Sven Dietrich <sdietrich@novell.com>
Subject: Re: PCI, ACPI, IRQ, IOAPIC: reroute PCI interrupt to legacy boot interrupt equivalent
Date: Wed, 14 Jan 2009 09:52:24 -0700 [thread overview]
Message-ID: <200901140952.24757.bjorn.helgaas@hp.com> (raw)
In-Reply-To: <20090114155529.GP25512@suse.de>
On Wednesday 14 January 2009 08:55:29 am Olaf Dabrunz wrote:
> On 14-Jan-09, Bjorn Helgaas wrote:
> > On Wednesday 14 January 2009 02:57:22 am Stefan Assmann wrote:
> > > Shaohua Li wrote:
> > > > So a device can generate interrupt from two irqs. And we can get the irq
> > > > number for the routing table. Can we extend the irq mechanism and
> > > > automatically register the interrupt handler for the two irqs?
> > >
> > > This would not solve the problem of asserting 2 different interrupt
> > > lines, in the masked interrupt handling case, for 1 interrupt request.
> > > The result would be that the ISR is called twice and at the second call
> > > you can't be sure that the device hasn't already been serviced.
> >
> > Calling the ISR twice isn't a problem, is it? We're talking about
> > PCI interrupts, which are shareable, so ISRs have to handle being
> > called extra times.
> >
> > There's still the problem that the core will disable an IRQ if we
> > take it too many times without any ISR that cares about it. But that's
> > a core issue, not an ISR issue.
>
> It is not solvable in the core. How do you find out that the "nobody
> cared" spurious IRQ is benign?
Sorry, I'm not suggesting that you can. I was just trying to clarify
that the problem is not with calling an ISR twice, but I think I only
managed to muddy the discussion to no benefit.
Bjorn
prev parent reply other threads:[~2009-01-14 16:52 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-09 23:03 PCI, ACPI, IRQ, IOAPIC: reroute PCI interrupt to legacy boot interrupt equivalent Len Brown
2009-01-12 11:09 ` Stefan Assmann
2009-01-12 11:37 ` Ingo Molnar
2009-01-12 18:51 ` Bjorn Helgaas
2009-01-12 19:25 ` Jon Masters
2009-01-12 19:45 ` Bjorn Helgaas
2009-01-13 13:32 ` Stefan Assmann
2009-01-13 18:22 ` Olaf Dabrunz
2009-01-15 15:34 ` Olaf Dabrunz
2009-01-12 23:36 ` Eric W. Biederman
2009-01-13 0:29 ` Jon Masters
2009-01-13 1:47 ` Ingo Molnar
2009-01-13 3:47 ` Eric W. Biederman
2009-01-13 4:26 ` Jon Masters
2009-01-14 11:40 ` Ingo Molnar
2009-01-14 19:18 ` Jon Masters
2009-01-14 22:42 ` Eric W. Biederman
2009-01-14 22:53 ` Steven Rostedt
2009-01-14 22:56 ` Jon Masters
2009-01-15 12:36 ` Olaf Dabrunz
2009-01-15 10:16 ` Stefan Assmann
2009-01-13 11:18 ` Stefan Assmann
2009-01-13 15:57 ` Olaf Dabrunz
2009-01-15 0:10 ` Bjorn Helgaas
2009-01-15 14:08 ` Stefan Assmann
2009-01-13 8:25 ` Shaohua Li
2009-01-14 9:57 ` Stefan Assmann
2009-01-14 15:48 ` Bjorn Helgaas
2009-01-14 15:55 ` Olaf Dabrunz
2009-01-14 16:52 ` Bjorn Helgaas [this message]
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=200901140952.24757.bjorn.helgaas@hp.com \
--to=bjorn.helgaas@hp.com \
--cc=jbarnes@virtuousgeek.org \
--cc=lenb@kernel.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=od@suse.de \
--cc=rostedt@goodmis.org \
--cc=sassmann@suse.de \
--cc=sdietrich@novell.com \
--cc=shaohua.li@intel.com \
--cc=tglx@linutronix.de \
/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).