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From: Sudeep Holla <sudeep.holla@arm.com>
To: Jon Mason <jon.mason@broadcom.com>
Cc: Russell King <linux@armlinux.org.uk>,
	Sudeep Holla <sudeep.holla@arm.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC 1/1] ARM: print MHz in /proc/cpuinfo
Date: Wed, 8 Jun 2016 09:34:06 +0100	[thread overview]
Message-ID: <5757D87E.2080508@arm.com> (raw)
In-Reply-To: <1465333713-14339-2-git-send-email-jon.mason@broadcom.com>



On 07/06/16 22:08, Jon Mason wrote:
> Query the CPU core clock in the device tree to determine the core clock
> speed.

How do guarantee that it's the current frequency of the CPU ?
It doesn't even represent the mix or max frequency, so it's incorrect.
Some DTs have boot frequency in that entry.

> Output this clock rate in /proc/cpuinfo to match the output
> from other architectures.  The output is intentionally patterned after
> the x86 output, to match existing (and possibly expected) convention.
>
> If any errors are encountered in querying the clock (or the speed is
> erroneously zero), nothing will be printed out.  Thus any existing
> devices that do not have CPU clocks defined in the device tree will
> work as before.
>

What if they just don't have in DT but have DVFS support ?

Also whey do we need this support when the user-space can query the
CPUFreq sysfs which is more accurate and maintains the current running
frequency ?

-- 
Regards,
Sudeep

  reply	other threads:[~2016-06-08  8:34 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-07 21:08 [RFC 0/1] " Jon Mason
2016-06-07 21:08 ` [RFC 1/1] " Jon Mason
2016-06-08  8:34   ` Sudeep Holla [this message]
2016-06-08 19:31     ` Jon Mason
2016-06-09  9:09       ` Sudeep Holla
2016-06-09 17:36         ` Jon Mason
2016-06-07 22:18 ` [RFC 0/1] " Russell King - ARM Linux
2016-06-07 22:58   ` Jon Mason
2016-07-02 23:58   ` Jon Masters
2016-07-03 16:54     ` Russell King - ARM Linux
2016-07-03 18:49       ` Andrew Lunn
2016-07-03 19:10         ` Russell King - ARM Linux
2016-07-18 10:02       ` Pavel Machek

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