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Date:   Tue, 9 Nov 2021 07:00:01 -0800
From:   Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        linux-pm@vger.kernel.org, x86@kernel.org,
        linux-doc@vger.kernel.org, Len Brown <len.brown@intel.com>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        Aubrey Li <aubrey.li@linux.intel.com>,
        Amit Kucheria <amitk@kernel.org>,
        Andi Kleen <ak@linux.intel.com>,
        Tim Chen <tim.c.chen@linux.intel.com>,
        "Ravi V. Shankar" <ravi.v.shankar@intel.com>,
        Ricardo Neri <ricardo.neri@intel.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/7] thermal: intel: hfi: Enable notification interrupt
Message-ID: <20211109150001.GA20404@ranerica-svr.sc.intel.com>
References: <20211106013312.26698-1-ricardo.neri-calderon@linux.intel.com>
 <20211106013312.26698-6-ricardo.neri-calderon@linux.intel.com>
 <YYjnUM/v8LmtnBq3@hirez.programming.kicks-ass.net>
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On Mon, Nov 08, 2021 at 10:01:04AM +0100, Peter Zijlstra wrote:
> On Fri, Nov 05, 2021 at 06:33:10PM -0700, Ricardo Neri wrote:
> > +	/*
> > +	 * On most systems, all CPUs in the package receive a package-level
> > +	 * thermal interrupt when there is an HFI update. Since they all are
> > +	 * dealing with the same update (as indicated by the update timestamp),
> > +	 * it is sufficient to let a single CPU to acknowledge the update and
> > +	 * schedule work to process it.
> > +	 */
> 
> That's pretty crap hardware behaviour. Is there really no way to steer
> these interrupts?

The HFI is a package-level thermal interrupt. Hence, all CPUs get it.
AFAIK there is no way to steer the interrupts.

Thanks and BR,
Ricardo