Re: [PATCH 5.15.y] powercap: intel_rapl: Do not change CLAMPING bit if ENABLE bit cannot be changed

[srinivas pandruvada <srinivas.pandruvada@linux.intel.com>]

On Wed, 2025-07-23 at 11:06 -0400, Sasha Levin wrote:
> On Wed, Jul 23, 2025 at 06:48:08AM -0700, srinivas pandruvada wrote:
> > On Wed, 2025-07-23 at 12:11 +0530, Harshit Mogalapalli wrote:
> > > > +	/* Check if the ENABLE bit was actually changed */
> > > > +	ret = rapl_read_data_raw(rd, PL1_ENABLE, true, &val);
> > > > +	if (ret) {
> > > > +		cpus_read_unlock();
> > > > +		return ret;
> > > > +	}
> > > 
> > > Shouldn't this be rapl_read_data_raw(rd, PL1_ENABLE, false,
> > > &val); ?
> > > 
> > > 
> > Correct. This will result in additional call to rapl_unit_xlate(),
> > but
> > since for primitive PL1_ENABLE, the unit is ARBITRARY_UNIT, this
> > will
> > not translate and return the same value.
> 
> I was thinking we need to call rapl_unit_xlate() so we won't just get
> whatever the raw value is, but yes - since it's ARBITRARY_UNIT then
> it
> won't really do much.
> 
> I guess in this case it doesn't really matter if we pass true or
> false
> here?

correct, you just save one additional call.

Thanks,
Srinivas

>