Re: [PATCH v4 4/5] arm64/perf: Enable PMCR long cycle counter bit

From: Jan Glauber
Date: Mon Feb 22 2016 - 07:45:34 EST


On Thu, Feb 18, 2016 at 05:34:28PM +0000, Will Deacon wrote:
> On Thu, Feb 18, 2016 at 05:50:13PM +0100, Jan Glauber wrote:
> > With the long cycle counter bit (LC) disabled the cycle counter is not
> > working on ThunderX SOC (ThunderX only implements Aarch64).
> > Also, according to documentation LC == 0 is deprecated.
> >
> > To keep the code simple the patch does not introduce 64 bit wide counter
> > functions. Instead writing the cycle counter always sets the upper
> > 32 bits so overflow interrupts are generated as before.
> >
> > Original patch from Andrew Pinksi <Andrew.Pinksi@xxxxxxxxxxxxxxxxxx>
>
> What does this mean? Do we need Andrew's S-o-B, or is this a fresh patch?

Hi Will,

Please let me know if I should repost or not, FWIW I got Andrew's S-o-B on the
patch.

Thanks, Jan

> Will