From: thomas.petazzoni@free-electrons.com (Thomas Petazzoni)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 0/5] Armada 370/XP clocksource fixes
Date: Thu, 8 Aug 2013 10:05:37 +0200 [thread overview]
Message-ID: <20130808100537.3d8e0980@skate> (raw)
In-Reply-To: <20130808071206.GA29815@lunn.ch>
Dear Andrew Lunn,
On Thu, 8 Aug 2013 09:12:06 +0200, Andrew Lunn wrote:
> On Wed, Aug 07, 2013 at 08:52:31PM -0300, Ezequiel Garcia wrote:
> > This small patchset fixes a somewhat minor issue found in the clocksource
> > driver for Armada 370/XP SoC.
> >
> > The Armada 370 SoC has no 25 MHz fixed timer, while the Armada XP SoC cannot
> > work properly without such 25 MHz fixed timer selected.
>
> Hi Ezequiel
>
> Is the XP case a silicon bug, or a design feature? If its a silicon
> bug, is it likely to be fixed in later steppings of the SOCs? If this
> feature is to come back, might we want to keep the property?
My understanding is that it's a design feature. Using the non-25 Mhz
timer leads to using a clocksource whose frequency varies when doing
cpufreq frequency changes, which isn't nice to handle. The fixed 25
Mhz was added in Armada XP to solve this problem, as far as I
understood.
Thanks,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
prev parent reply other threads:[~2013-08-08 8:05 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-07 23:52 [PATCH 0/5] Armada 370/XP clocksource fixes Ezequiel Garcia
2013-08-07 23:52 ` [PATCH 1/5] clocksource: armada-370-xp: Use CLOCKSOURCE_OF_DECLARE Ezequiel Garcia
2013-08-07 23:52 ` [PATCH 2/5] clocksource: armada-370-xp: Simplify TIMER_CTRL register access Ezequiel Garcia
2013-08-08 7:20 ` Andrew Lunn
2013-08-08 9:29 ` Ezequiel Garcia
2013-08-07 23:52 ` [PATCH 3/5] clocksource: armada-370-xp: Introduce new compatibles Ezequiel Garcia
2013-08-08 7:53 ` Andrew Lunn
2013-08-08 9:27 ` Ezequiel Garcia
2013-08-07 23:52 ` [PATCH 4/5] clocksource: armada-370-xp: Fix device-tree binding Ezequiel Garcia
2013-08-08 10:44 ` Jason Cooper
2013-08-07 23:52 ` [PATCH 5/5] ARM: mvebu: Fix the Armada 370/XP timer compatible strings Ezequiel Garcia
2013-08-08 7:12 ` [PATCH 0/5] Armada 370/XP clocksource fixes Andrew Lunn
2013-08-08 8:05 ` Thomas Petazzoni [this message]
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