All of lore.kernel.org
 help / color / mirror / Atom feed
From: Stephen Caudle <scaudle@codeaurora.org>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: dwalker@codeaurora.org, linux-arm-msm@vger.kernel.org,
	adharmap@codeaurora.org, linux-kernel@vger.kernel.org,
	miltonm@bga.com, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] [ARM] gic: Unmask private interrupts on all cores during IRQ enable
Date: Wed, 01 Dec 2010 11:36:10 -0500	[thread overview]
Message-ID: <4CF6797A.2010807@codeaurora.org> (raw)
In-Reply-To: <20101130180718.GB8521@n2100.arm.linux.org.uk>

On 11/30/2010 01:07 PM, Russell King - ARM Linux wrote:
> Sorry, missed this.
>
> If it's a private peripheral, it can only be accessed from its associated
> CPU.  What that means is you don't want to enable the interrupt on other
> CPUs as the peripheral may not be present or initialized on that CPU.

Understood.  But the alternative is to require all code that requests a 
PPI to have to enable the IRQ on the other cores.  This seems 
unreasonable to me.

> So I'm nervous about this change - architecturally it feels like the
> wrong thing to do to take the PPI interrupts through the generic IRQ
> infrastructure.

What do suggest as an alternative to this solution?  Creating separate 
IRQ numbers for each core (per PPI) doesn't seem to scale well as the 
number of cores increase.

~Stephen

-- 
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

WARNING: multiple messages have this Message-ID (diff)
From: scaudle@codeaurora.org (Stephen Caudle)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] [ARM] gic: Unmask private interrupts on all cores during IRQ enable
Date: Wed, 01 Dec 2010 11:36:10 -0500	[thread overview]
Message-ID: <4CF6797A.2010807@codeaurora.org> (raw)
In-Reply-To: <20101130180718.GB8521@n2100.arm.linux.org.uk>

On 11/30/2010 01:07 PM, Russell King - ARM Linux wrote:
> Sorry, missed this.
>
> If it's a private peripheral, it can only be accessed from its associated
> CPU.  What that means is you don't want to enable the interrupt on other
> CPUs as the peripheral may not be present or initialized on that CPU.

Understood.  But the alternative is to require all code that requests a 
PPI to have to enable the IRQ on the other cores.  This seems 
unreasonable to me.

> So I'm nervous about this change - architecturally it feels like the
> wrong thing to do to take the PPI interrupts through the generic IRQ
> infrastructure.

What do suggest as an alternative to this solution?  Creating separate 
IRQ numbers for each core (per PPI) doesn't seem to scale well as the 
number of cores increase.

~Stephen

-- 
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

  reply	other threads:[~2010-12-01 16:36 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-03 21:46 [PATCH v2] [ARM] gic: Unmask private interrupts on all cores during IRQ enable Stephen Caudle
2010-11-03 21:46 ` Stephen Caudle
2010-11-30 15:42 ` Stephen Caudle
2010-11-30 15:42   ` Stephen Caudle
2010-11-30 18:07 ` Russell King - ARM Linux
2010-11-30 18:07   ` Russell King - ARM Linux
2010-12-01 16:36   ` Stephen Caudle [this message]
2010-12-01 16:36     ` Stephen Caudle
2010-12-01 17:14     ` Russell King - ARM Linux
2010-12-01 17:14       ` Russell King - ARM Linux
2010-12-09 16:24       ` Stephen Caudle
2010-12-09 16:24         ` Stephen Caudle
2010-12-16 14:54         ` Stephen Caudle
2010-12-16 14:54           ` Stephen Caudle
2010-12-16 15:03           ` Russell King - ARM Linux
2010-12-16 15:03             ` Russell King - ARM Linux
2010-12-16 15:08             ` Stephen Caudle
2010-12-16 15:08               ` Stephen Caudle

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4CF6797A.2010807@codeaurora.org \
    --to=scaudle@codeaurora.org \
    --cc=adharmap@codeaurora.org \
    --cc=dwalker@codeaurora.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@arm.linux.org.uk \
    --cc=miltonm@bga.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.