From: Eugene Surovegin <ebs@ebshome•net>
To: Shawn Jin <shawnxjin@gmail•com>
Cc: ppcembed <linuxppc-embedded@ozlabs•org>
Subject: Re: Interrupt prioritization on linux for ppc440
Date: Fri, 15 Apr 2005 15:12:35 -0700 [thread overview]
Message-ID: <20050415221235.GA29802@gate.ebshome.net> (raw)
In-Reply-To: <c3d0340b05041514362746169a@mail.gmail.com>
On Fri, Apr 15, 2005 at 02:36:51PM -0700, Shawn Jin wrote:
>
> The home-made interrupt controller PIC supports interrupt priorities
> and critical/non-critical interrupts. I found that the current kernel
> doesn't support interrupt priorities.
Yes, we don't have IRQ priorities on 4xx. Theoretically, they can be
emulated in get_irq, but I really don't think it's worth it.
> Is this observation true? Is
> there any existing patch to support that?
I'm not aware of such patch existence.
> I noticed that the implementation of ppc4xx_pic.c disables all
> critical interrupts during initialization. To support critical
> interrupts, is it so simple that we change the handler of critical
> exception from CriticalInput to do_IRQ in head_44x.S?
No, it's not that simple. Linux doesn't support a notion of critical
IRQs versus normal ones. Until there is an infrastructure for this, it
doesn't make any sense to implement 4xx support.
--
Eugene
next prev parent reply other threads:[~2005-04-15 22:12 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-04-15 21:36 Interrupt prioritization on linux for ppc440 Shawn Jin
2005-04-15 22:12 ` Eugene Surovegin [this message]
2005-04-15 23:09 ` Shawn Jin
2005-04-16 0:50 ` Eugene Surovegin
2005-04-18 21:14 ` Shawn Jin
2005-04-18 22:06 ` Eugene Surovegin
2005-04-18 23:11 ` Shawn Jin
2005-04-19 0:27 ` Eugene Surovegin
2005-04-18 17:01 ` Lawrence E. Bakst
2005-04-18 17:25 ` Eugene Surovegin
2005-04-18 20:54 ` Lawrence E. Bakst
2005-04-18 22:27 ` Eugene Surovegin
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