From: "Richard B. Johnson" <root@chaos.analogic.com>
To: Michael Frank <mhf@linuxmail.org>
Cc: Russell King <rmk+lkml@arm.linux.org.uk>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
"Grover, Andrew" <andrew.grover@intel.com>,
Mark Gross <mgross@linux.co.intel.com>,
arjanv@redhat.com, Tim Bird <tim.bird@am.sony.com>,
Linux Kernel list <linux-kernel@vger.kernel.org>
Subject: Re: Why no interrupt priorities?
Date: Fri, 27 Feb 2004 08:45:28 -0500 (EST) [thread overview]
Message-ID: <Pine.LNX.4.53.0402270838210.6853@chaos> (raw)
In-Reply-To: <opr306i5cm4evsfm@smtp.pacific.net.th>
On Fri, 27 Feb 2004, Michael Frank wrote:
> On Fri, 27 Feb 2004 09:05:48 +0000, Russell King <rmk+lkml@arm.linux.org.uk> wrote:
>
> > On Fri, Feb 27, 2004 at 02:26:31PM +0800, Michael Frank wrote:
> >> Is this to imply that edge triggered shared interrupts are used anywhere?
> >
> > It is (or used to be) rather common with serial ports. Remember that
> > COM1 and COM3 were both defined to use IRQ4 and COM2 and COM4 to use
> > IRQ3.
> >
> >> Never occured to me to use shared IRQ's edge triggered as this mode
> >> _cannot_ work reliably for HW limitations.
> >
> > The serial driver takes great care with this - when we service such an
> > interrupt, we keep going until we have scanned all the devices until
> > such time that we can say "all devices are no longer signalling an
> > interrupt".
> >
> > This is something it has always done - it's nothing new.
> >
>
> Sorry, i think the serial driver IRQ is level triggered :)
CPU0 CPU1
0: 7904936 7922491 IO-APIC-edge timer
1: 74277 70096 IO-APIC-edge keyboard
2: 0 0 XT-PIC cascade
3: 535 556 IO-APIC-edge serial <--- EDGE
4: 2 1 IO-APIC-edge serial <--- EDGE
10: 3435637 3440251 IO-APIC-level eth0
11: 295018 296838 IO-APIC-level BusLogic BT-958
13: 4567 4591 IO-APIC-level Analogic(tm) AMX/AFF Driver
14: 1331 1239 IO-APIC-level Analogic(tm) DSP/DSS Driver
15: 2 3 IO-APIC-level Analogic(tm) VXI/MSG Driver
NMI: 0 0
LOC: 15826338 15826337
ERR: 0
MIS: 2
Cheers,
Dick Johnson
Penguin : Linux version 2.4.24 on an i686 machine (797.90 BogoMips).
Note 96.31% of all statistics are fiction.
next prev parent reply other threads:[~2004-02-27 13:44 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-02-27 1:36 Grover, Andrew
2004-02-27 3:02 ` Randy.Dunlap
2004-02-29 8:32 ` Michael Frank
2004-02-29 8:36 ` Arjan van de Ven
2004-02-29 9:52 ` Michael Frank
2004-02-27 5:32 ` Benjamin Herrenschmidt
2004-02-27 6:26 ` Michael Frank
2004-02-27 6:46 ` Benjamin Herrenschmidt
2004-02-27 9:05 ` Russell King
2004-02-27 13:31 ` Michael Frank
2004-02-27 13:45 ` Richard B. Johnson [this message]
2004-02-27 13:50 ` Russell King
2004-02-27 14:51 ` Michael Frank
2004-02-27 7:25 ` Arjan van de Ven
2004-02-27 10:15 ` Helge Hafting
2004-02-27 18:32 ` Mike Fedyk
-- strict thread matches above, loose matches on Subject: below --
2004-02-27 17:44 Grover, Andrew
2004-02-27 18:15 ` Chris Friesen
2004-02-27 18:42 ` Richard B. Johnson
2004-02-27 19:42 ` Michael Frank
2004-02-27 19:11 ` Michael Frank
2004-02-27 18:55 ` Matt Mackall
2004-02-27 19:09 ` Tim Hockin
2004-02-27 20:29 ` Matt Mackall
2004-02-27 19:19 ` Michael Frank
2004-02-27 20:53 ` Jesse Pollard
2004-02-29 9:43 ` Michael Frank
2004-03-01 16:57 ` Jesse Pollard
2004-03-01 17:35 ` Michael Frank
2004-03-02 15:25 ` Jesse Pollard
2004-02-27 11:37 Etienne Lorrain
2004-02-27 13:24 ` Michael Frank
[not found] <mailman.1077822002.21081.linux-kernel2news@redhat.com>
2004-02-27 8:00 ` Pete Zaitcev
2004-02-26 23:47 Albert Cahalan
2004-02-26 19:05 Tim Bird
2004-02-26 19:39 ` Richard B. Johnson
2004-02-26 21:02 ` Tim Bird
2004-02-26 21:30 ` Arjan van de Ven
2004-02-26 22:21 ` Mark Gross
2004-02-27 7:14 ` Arjan van de Ven
2004-02-27 11:27 ` Ingo Oeser
2004-02-27 11:52 ` Arjan van de Ven
2004-02-27 13:23 ` Richard B. Johnson
2004-02-27 12:04 ` Christoph Hellwig
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