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

[Dmitry Osipenko]

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@xxxxxxxxx>
>> ---
>>  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.

I guess it's not clear by looking at this patch, please see a full
version of the function:

int _opp_compare_key(struct dev_pm_opp *opp1, struct dev_pm_opp *opp2,
         bool rate_not_available)
{
  if (!rate_not_available && opp1->rate != opp2->rate)
    return opp1->rate < opp2->rate ? -1 : 1;
  if (opp1->bandwidth && opp2->bandwidth &&
      opp1->bandwidth[0].peak != opp2->bandwidth[0].peak)
    return opp1->bandwidth[0].peak < opp2->bandwidth[0].peak ? -1 : 1;
  if (opp1->level != opp2->level)
    return opp1->level < opp2->level ? -1 : 1;
  return 0;
}

Perhaps we could check whether opp1->rate=0, like it's done for the
opp1->bandwidth. I'll consider this variant for v3, thanks.