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X-Envelope-From: stefanr@s5r6.in-berlin.de
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Date: Fri, 21 Mar 2008 17:31:11 +0100
From: Stefan Richter <stefanr@s5r6.in-berlin.de>
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To: Martin Michlmayr <tbm@cyrius.com>
CC: linux1394-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org
Subject: Re: nobody cared about IRQ 19 (firewire, on a HP 2510p notebook)
References: <20080321153952.GA26354@deprecation.cyrius.com>
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Martin Michlmayr wrote:
> I just got the following in dmesg a few minutes after booting my
> notebook which was idle at the time this occurred.  This was with
> 2.6.25-rc6 but I've seen the same with 2.6.22 (see the attached
> dmesg from 2.6.22).
> 
> irq 19: nobody cared (try booting with the "irqpoll" option)
> Pid: 0, comm: swapper Not tainted 2.6.25-rc6-amd64 #1
> 
> Call Trace:
>  <IRQ>  [<ffffffff80271c0b>] __report_bad_irq+0x38/0x7c
>  [<ffffffff80271e51>] note_interrupt+0x202/0x249
>  [<ffffffff8027274e>] handle_fasteoi_irq+0xab/0xd0
>  [<ffffffff8020f82c>] do_IRQ+0x6e/0xda
>  [<ffffffff8020c65d>] ret_from_intr+0x0/0x19
>  <EOI>  [<ffffffff80221831>] ? native_irq_enable+0x6/0x7
>  [<ffffffff88006330>] ? :processor:acpi_idle_enter_bm+0x2ab/0x325
>  [<ffffffff803b5ef3>] ? menu_select+0x70/0x99
>  [<ffffffff803b52e1>] ? cpuidle_idle_call+0x77/0xa6
>  [<ffffffff803b526a>] ? cpuidle_idle_call+0x0/0xa6
>  [<ffffffff8020b187>] ? cpu_idle+0xb1/0xdb
>  [<ffffffff8042ea16>] ? rest_init+0x5a/0x5c
> 
> handlers:
> [<ffffffff8806f0f5>] (irq_handler+0x0/0x207 [firewire_ohci])
> Disabling IRQ #19
...
> 02:06.1 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 IEEE 1394 Controller (rev 04)
...

According to your 2.6.22 dmesg, this happens a while after the firewire 
subsystem seemingly successfully initialized the controller.  Could you 
please post "dmesg | grep firewire" from 2.6.25-rc6 though?

The __report_bad_irq() and "Disabling IRQ #..." can only have happened 
because this condition in fw-ohci.c::irq_handler()

	event = reg_read(ohci, OHCI1394_IntEventClear);

	if (!event || !~event)
		return IRQ_NONE;

happened a lot of times.  This means either
   - Some MMIO reads return bogus values (all zero or all ones in a
     bitfield which should be sparsely populated in a proper interrupt
     event),
or
   - the interrupt was misrouted by the kernel's IRQ infrastructure was
     unable to detect the misrouting, AFAIU.
-- 
Stefan Richter
-=====-==--- --== =-=-=
http://arcgraph.de/sr/
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