From mboxrd@z Thu Jan  1 00:00:00 1970
From: linux@arm.linux.org.uk (Russell King - ARM Linux)
Date: Mon, 11 Jun 2012 16:57:16 +0100
Subject: [PATCH] ARM: formalize an IPI for CPU wake-ups
In-Reply-To: <alpine.LFD.2.02.1206111152190.23555@xanadu.home>
References: <alpine.LFD.2.02.1206111152190.23555@xanadu.home>
Message-ID: <20120611155716.GA18267@n2100.arm.linux.org.uk>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Mon, Jun 11, 2012 at 11:54:03AM -0400, Nicolas Pitre wrote:
> 
> Many CPUs are implementing power saving states via the WFI mode.
> In some cases, WFI must be entered in order to suspend, or even reset,
> a CPU.
> 
> Whether a CPU needs to be awaken, brought out of WFI during secondary
> boot, or to cancel a reset state before it is effective, the CPU must
> receive an interrupt to exit its WFI state.
> 
> Let's formalize an IPI number for this purpose, and move over existing
> users over to a convenience function for it.
> 
> This also has the side effect of removing the spurious "Unknown IPI
> message 1" each time a CPU is awaken.

I want people to move over to using IPI 0 for wakeup.

The problem is, as ever, no one bloody well listens and they all continue
on copying Realview.