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Re: [PATCH] Import updates from i386's i8259.c

To: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Subject: Re: [PATCH] Import updates from i386's i8259.c
From: "Maciej W. Rozycki" <macro@linux-mips.org>
Date: Wed, 6 Dec 2006 13:48:02 +0000 (GMT)
Cc: Ingo Molnar <mingo@redhat.com>, anemo@mba.sphere.ne.jp, Ralf Baechle <ralf@linux-mips.org>, linux-mips@linux-mips.org
In-reply-to: <4576C2E9.4060900@ru.mvista.com>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <20061206.103923.71086192.nemoto@toshiba-tops.co.jp> <20061206015818.GB27985@linux-mips.org> <20061206.115602.63741871.nemoto@toshiba-tops.co.jp> <20061206.133836.89067271.nemoto@toshiba-tops.co.jp> <4576C2E9.4060900@ru.mvista.com>
Sender: linux-mips-bounce@linux-mips.org
On Wed, 6 Dec 2006, Sergei Shtylyov wrote:

> > +static struct irq_chip i8259A_chip = {
> > +   .name           = "XT-PIC",
> > +   .mask           = disable_8259A_irq,
> > +   .unmask         = enable_8259A_irq,
> > +   .mask_ack       = mask_and_ack_8259A,
> >  };
> 
>    I wonder whose idea was to call this device XT-PIC. XT never had dual 8259A
> PICs and so was capable of handling only 8 IRQs. Dual 8259A was first used in
> the AT class machines...

 Ask Ingo, perhaps... ;-)  I think he was perfectly right, though -- this 
is a pair of PC/XT-class PICs.  And with the "IO-APIC-edge" and 
"IO-APIC-level" alternatives back when the concept of IRQ controllers was 
introduced, "XT-PIC" rather than "8259A" sounded quite right.

  Maciej

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