linux-kernel - Re: [PATCH] clocksource: Add debugfs support

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Message-ID: <87d08suo0y.fsf@nanos.tec.linutronix.de>
Date:   Wed, 01 Apr 2020 01:01:49 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Thierry Reding <thierry.reding@...il.com>
Cc:     John Stultz <john.stultz@...aro.org>,
        Stephen Boyd <sboyd@...nel.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] clocksource: Add debugfs support

Thierry Reding <thierry.reding@...il.com> writes:
> On Wed, Apr 01, 2020 at 12:06:37AM +0200, Thomas Gleixner wrote:
>> It does not provide any information about the clocksource, it provides
>> an interface to read the counter - nothing else.
>
> The counter is part of the information about a clocksource, isn't it?

Sorry to be pedantic, but no. Information about a clocksource is the
name, the type, the frequency, bitwidth etc.

The counter file is not providing information about the
clocksource. It's exposing an accessor to the clocksource itself.

> I can also add some information about what I intend to use this for,
> though it'll be a bit boring because I really only want this as a way
> of testing that I'm reading from the right registers and that these
> counters are running. A debugfs interface seemed like a better and more
> widely useful way to achieve that than implementing some one-off hack to
> poll those registers.

But how much value has this interface beyond the 'hack a driver for a
new clocksource' experience?

To me none, but that might be my personal skewed view.

Thanks,

        tglx