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From: cov@codeaurora.org (Christopher Covington)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 1/4] ARM: arch_timers: enable the use of the virtual timer
Date: Tue, 17 Jul 2012 12:41:01 -0400	[thread overview]
Message-ID: <5005959D.3050407@codeaurora.org> (raw)
In-Reply-To: <1341566422-20368-2-git-send-email-marc.zyngier@arm.com>

Hi Marc,

Here's one additional small question about your explanation in the
commit message.

On 07/06/2012 05:20 AM, Marc Zyngier wrote:
> At the moment, the arch_timer driver only uses the physical timer,
> which can cause problem if PL2 hasn't enabled PL1 access in CNTHCTL,
> which is likely in a virtualized environment. Instead, the virtual
> timer is always available.

If the virtual timer is "always available", why would a device tree
description of the hardware leave that interrupt number out as described
below?

> This patch enables the use of both the virtual timer, unless no
> interrupt is provided in the DT for it, in which case is falls
> back to the physical timer.

[...]

Thanks,
Christopher

-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum

  parent reply	other threads:[~2012-07-17 16:41 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-06  9:20 [RFC PATCH 0/4] arch_timers patches to enable KVM support Marc Zyngier
2012-07-06  9:20 ` [RFC PATCH 1/4] ARM: arch_timers: enable the use of the virtual timer Marc Zyngier
2012-07-16 21:12   ` Christopher Covington
2012-07-17 16:41   ` Christopher Covington [this message]
2012-07-06  9:20 ` [RFC PATCH 2/4] ARM: arch_timers: register a time/cycle counter Marc Zyngier
2012-07-17 16:41   ` Christopher Covington
2012-07-06  9:20 ` [RFC PATCH 3/4] ARM: arch_timers: give the virtual timer its own interrupt handler Marc Zyngier
2012-07-17 16:57   ` Christopher Covington
2012-07-06  9:20 ` [RFC PATCH 4/4] ARM: arch_timers: dynamic switch to physical timer and virtual timer offloading Marc Zyngier
2012-07-17 19:02   ` Christopher Covington

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