linux-kernel - Re: [PATCH v6 15/29] x86/hpet: Add helper function hpet_set_comparator

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Date:   Fri, 06 May 2022 23:41:13 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>,
        x86@...nel.org
Cc:     Tony Luck <tony.luck@...el.com>, Andi Kleen <ak@...ux.intel.com>,
        Stephane Eranian <eranian@...gle.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Joerg Roedel <joro@...tes.org>,
        Suravee Suthikulpanit <Suravee.Suthikulpanit@....com>,
        David Woodhouse <dwmw2@...radead.org>,
        Lu Baolu <baolu.lu@...ux.intel.com>,
        Nicholas Piggin <npiggin@...il.com>,
        "Ravi V. Shankar" <ravi.v.shankar@...el.com>,
        Ricardo Neri <ricardo.neri@...el.com>,
        iommu@...ts.linux-foundation.org, linuxppc-dev@...ts.ozlabs.org,
        linux-kernel@...r.kernel.org,
        Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>
Subject: Re: [PATCH v6 15/29] x86/hpet: Add helper function
 hpet_set_comparator_periodic()

On Thu, May 05 2022 at 16:59, Ricardo Neri wrote:
> Programming an HPET channel as periodic requires setting the
> HPET_TN_SETVAL bit in the channel configuration. Plus, the comparator
> register must be written twice (once for the comparator value and once for
> the periodic value). Since this programming might be needed in several
> places (e.g., the HPET clocksource and the HPET-based hardlockup detector),
> add a helper function for this purpose.
>
> A helper function hpet_set_comparator_oneshot() could also be implemented.
> However, such function would only program the comparator register and the
> function would be quite small. Hence, it is better to not bloat the code
> with such an obvious function.

This word salad above does not provide a single reason why the periodic
programming function is required and better suited for the NMI watchdog
case and then goes on and blurbs about why a function which is not
required is not implemented. The argument about not bloating the code
with an "obvious???" function which is quite small is slightly beyond my
comprehension level.

Thanks,

        tglx