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Date: Mon, 14 Feb 2011 12:34:57 +0100
From: Alexander Graf <agraf@suse.de>
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Subject: [Qemu-devel] Re: [RFC] prep: enable irq sharing on ide again
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To: Gerd Hoffmann <kraxel@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>, =?UTF-8?B?QW5kcmVhcyBGw6RyYmU=?= =?UTF-8?B?cg==?= <andreas.faerber@web.de>, QEMU Developers <qemu-devel@nongnu.org>, Aurelien Jarno <aurelien@aurel32.net>

Gerd Hoffmann wrote:
> On 02/08/11 00:26, Alexander Graf wrote:
>> The new ISA infrastructure checks for potential irq sharing bugs on
>> interrupt lines, because usually irq lines on isa can't be shared.
>>
>> The PREP spec however mandates that the irq lines for both IDE ports
>> are shared and according to Aurelien this also used to work just fine.
>>
>> So let's add a way to enable this sharing again, so we don't introduce
>> unnecessary regressions over older versions of Qemu.
>
> Had a patch for that, got shoot down for reasons I don't remember,
> attached for reference.  It basically allows IRQ sharing in case the
> two devices sharing the IRQ are of the same kind.  In that case you
> usually have a single guest driver handling both devices and IRQ
> sharing works most of the time.
>
> I don't mind much which approach we take ...

I'm very indifferent myself :). This is not an issue we should waste too
much time/effort on.


Alex