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From:   Joel Stanley <joel@jms.id.au>
Date:   Wed, 1 Sep 2021 23:38:19 +0000
Message-ID: <CACPK8Xfu7K0FosjnfaiETXVP+QX9fOtUE5PymegvHc3MaWy52A@mail.gmail.com>
Subject: Re: [PATCH 2/2] clocksource/drivers/fttmr010: Be stricter on IRQs
To:     =?UTF-8?Q?C=C3=A9dric_Le_Goater?= <clg@kaod.org>
Cc:     Guenter Roeck <linux@roeck-us.net>,
        Linus Walleij <linus.walleij@linaro.org>,
        Andrew Jeffery <andrew@aj.id.au>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-kernel <linux-kernel@vger.kernel.org>
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On Sat, 28 Aug 2021 at 08:08, C=C3=A9dric Le Goater <clg@kaod.org> wrote:

> AFAICT, the ast2600 does not use a fttmr010 clocksource.

Correct.

When doing bringup of the ast2600, I updated this driver to support
the new layout. Only once I'd submitted it did I learn that aspeed
preferred to use only the Cortex A7's timer source, and only that
source.

The armv7 timer can be lost when a core goes into power save mode, but
I am told the ast2600 does not implement power saving modes, so we set
the always-on property for the arm,armv7-timer. This allows us to use
the timer as a clocksource for hrtimers, removing the need to use the
fttmr010 driver at all.

Cheers,

Joel