linux-kernel - Re: [PATCH v2 19/48] opp: Fix adding OPP entries in a wrong order if rate is unavailable

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Date:   Wed, 23 Dec 2020 23:36:28 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Viresh Kumar <viresh.kumar@...aro.org>
Cc:     Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Mark Brown <broonie@...nel.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Peter Geis <pgwipeout@...il.com>,
        Nicolas Chauvet <kwizart@...il.com>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Kevin Hilman <khilman@...nel.org>,
        Peter De Schrijver <pdeschrijver@...dia.com>,
        Viresh Kumar <vireshk@...nel.org>,
        Stephen Boyd <sboyd@...nel.org>,
        Michael Turquette <mturquette@...libre.com>,
        devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        linux-media@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-clk@...r.kernel.org
Subject: Re: [PATCH v2 19/48] opp: Fix adding OPP entries in a wrong order if
 rate is unavailable

23.12.2020 07:34, Viresh Kumar пишет:
> On 22-12-20, 22:19, Dmitry Osipenko wrote:
>> 22.12.2020 12:12, Viresh Kumar пишет:
>>> On 17-12-20, 21:06, Dmitry Osipenko wrote:
>>>> Fix adding OPP entries in a wrong (opposite) order if OPP rate is
>>>> unavailable. The OPP comparison is erroneously skipped if OPP rate is
>>>> missing, thus OPPs are left unsorted.
>>>>
>>>> Signed-off-by: Dmitry Osipenko <digetx@...il.com>
>>>> ---
>>>>  drivers/opp/core.c | 23 ++++++++++++-----------
>>>>  drivers/opp/opp.h  |  2 +-
>>>>  2 files changed, 13 insertions(+), 12 deletions(-)
>>>>
>>>> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
>>>> index 34f7e530d941..5c7f130a8de2 100644
>>>> --- a/drivers/opp/core.c
>>>> +++ b/drivers/opp/core.c
>>>> @@ -1531,9 +1531,10 @@ static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
>>>>  	return true;
>>>>  }
>>>>  
>>>> -int _opp_compare_key(struct dev_pm_opp *opp1, struct dev_pm_opp *opp2)
>>>> +int _opp_compare_key(struct dev_pm_opp *opp1, struct dev_pm_opp *opp2,
>>>> +		     bool rate_not_available)
>>>>  {
>>>> -	if (opp1->rate != opp2->rate)
>>>> +	if (!rate_not_available && opp1->rate != opp2->rate)
>>>
>>> rate will be 0 for both the OPPs here if rate_not_available is true and so this
>>> change shouldn't be required.
>>
>> The rate_not_available is negated in the condition. This change is
>> required because both rates are 0 and then we should proceed to the
>> levels comparison.
> 
> Won't that happen without this patch ?

No