linux-kernel - Re: [PATCH 2/2] opp: Manage empty OPP tables with clk handle

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Date:   Wed, 3 Jul 2019 14:41:10 +0530
From:   Rajendra Nayak <rnayak@...eaurora.org>
To:     Viresh Kumar <viresh.kumar@...aro.org>
Cc:     vireshk@...nel.org, sboyd@...nel.org, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org
Subject: Re: [PATCH 2/2] opp: Manage empty OPP tables with clk handle

[]..
>>   
> 
> Explain the rationale behind this code here in a comment.
> 
>> +	if (!_get_opp_count(opp_table)) {
>> +		ret = _generic_set_opp_clk_only(dev, clk, freq);
>> +		goto put_opp_table;
>> +	}
>> +
>>   	temp_freq = old_freq;
>>   	old_opp = _find_freq_ceil(opp_table, &temp_freq);
>>   	if (IS_ERR(old_opp)) {
> 
> Also, rebase over the OPP branch please:

thanks, I will fix/rebase and repost,
in the meantime while I was testing this a little more I realized I also need
something like the change below to avoid a refcount mismatch WARN when empty OPP
table is removed using dev_pm_opp_of_remove_table()

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index fa7d4d6d37b3..20128a88baf2 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -2118,7 +2118,8 @@ void _dev_pm_opp_find_and_remove_table(struct device *dev)
                 return;
         }
  
-       _put_opp_list_kref(opp_table);
+       if (_get_opp_count(opp_table))
+               _put_opp_list_kref(opp_table);
  
         /* Drop reference taken by _find_opp_table() */
         dev_pm_opp_put_opp_table(opp_table);

Does this look like a good way to fix it?

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