linux-kernel - Re: [GIT PULL] thermal for v5.7-rc1

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Message-ID: <2422ce89-5b76-f56e-2b62-c120062ce642@linaro.org>
Date:   Wed, 8 Apr 2020 12:53:02 +0200
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     Linus Torvalds <torvalds@...ux-foundation.org>,
        Ingo Molnar <mingo@...nel.org>,
        Thara Gopinath <thara.gopinath@...aro.org>,
        Willy Wolff <willy.mh.wolff.ml@...il.com>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>
Cc:     Zhang Rui <rui.zhang@...el.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Linux PM mailing list <linux-pm@...r.kernel.org>,
        Amit Kucheria <amit.kucheria@...aro.org>
Subject: Re: [GIT PULL] thermal for v5.7-rc1


Hi Linus,

On 08/04/2020 05:14, Linus Torvalds wrote:
> On Tue, Apr 7, 2020 at 4:26 AM Daniel Lezcano <daniel.lezcano@...aro.org> wrote:
>>
>> git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux.git
>> tags/thermal-v5.7-rc1
> 
> Ho humm.
> 
> This caused a conflict between commit
> 
>   f12e4f66ab6a ("thermal/cpu-cooling: Update thermal pressure in case
> of a maximum frequency capping")
> 
> that came in through the scheduler updates from Ingo Molnar, and commit
> 
>   ff44f672d741 ("thermal/drivers/cpufreq_cooling: Fix return of
> cpufreq_set_cur_state")
> 
> from the thermal tree.
> 
> The conflict wasn't complicated, but the reason I mention it is that I
> resolved it in a way that neither of those commits had done.
> 
> In particular, the thermal tree did
> 
>   ret = freq_qos_update_request(..)
>   return ret < 0 ? ret : 0;
> 
> where that whole "return negative or zero" logic is new (it used to
> return positive values, the fix was to return zero instead).
> 
> The scheduler tree did
> 
>   ret = freq_qos_update_request(..)
>   if (ret > 0) {.. do thermal pressure thing ..}
>   return ret;
> 
> which obviously still returns that positive value.
> 
> My resolution to the conflict was to not take that return with a
> conditional operation, but instead just add a
> 
>   ret = 0;
> 
> to inside that thermal pressure if-statement, and avoid returning a
> non-zero positive value that way.
> 
> I just wanted both sides to be aware of my non-traditional merge
> resolution, and take a look.

The resolution looks correct to me.

Thanks

  -- Daniel


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