On 01/22/2015 02:46 AM, Stephen Boyd wrote:
> On 01/21, Tomeu Vizoso wrote:
>> Adds a way for clock consumers to set maximum and minimum rates. This
>> can be used for thermal drivers to set minimum rates, or by misc.
>> drivers to set maximum rates to assure a minimum performance level.
>>
>> Changes the signature of the determine_rate callback by adding the
>> parameters min_rate and max_rate.
>>
>> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
>>
>> ---
>> v11: * Recalculate the rate before putting the reference to clk_core
>> * Don't recalculate the rate when freeing the per-user clock
>> in the initialization error paths
>> * Move __clk_create_clk to be next to __clk_free_clk for more
>> comfortable reading
>
> Can we do this in the previous patch where we introduce the
> function?
Ok.
>> @@ -2143,9 +2314,16 @@ struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
>> else
>> clk->owner = NULL;
>>
>> + INIT_HLIST_HEAD(&clk->clks);
>> +
>> + hw->clk = __clk_create_clk(hw, NULL, NULL);
>> +
>> ret = __clk_init(dev, hw->clk);
>> - if (ret)
>> + if (ret) {
>> + __clk_free_clk(hw->clk);
>> + hw->clk = NULL;
>> return ERR_PTR(ret);
>> + }
>>
>> return hw->clk;
>> }
>> @@ -2210,12 +2388,16 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw)
>> }
>> }
>>
>> + INIT_HLIST_HEAD(&clk->clks);
>> +
>> hw->clk = __clk_create_clk(hw, NULL, NULL);
>> ret = __clk_init(dev, hw->clk);
>> if (!ret)
>> return hw->clk;
>>
>> - kfree(hw->clk);
>> + __clk_free_clk(hw->clk);
>> + hw->clk = NULL;
>
> Shouldn't we be assigning to NULL in the previous patch (same
> comment for __clk_register)?
Agreed, though I have gone ahead and removed __clk_register completely
because AFAICS it has never been used.
>> fail_parent_names_copy:
>> while (--i >= 0)
>> kfree(clk->parent_names[i]);
>> @@ -2420,7 +2602,14 @@ void __clk_put(struct clk *clk)
>> if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
>> return;
>>
>> + clk_prepare_lock();
>> + hlist_del(&clk->child_node);
>> + clk_prepare_unlock();
>> +
>> + clk_core_set_rate(clk->core, clk->core->req_rate);
>> +
>> clk_core_put(clk->core);
>> +
>
> Sad that we take the lock 3 times during __clk_put(). We should
> be able to do it only once if we have a lockless
> clk_core_set_rate() function and put the contents of
> clk_core_put() into this function. Actually we need to do that to
> be thread safe with clk->core->req_rate changing. We can call the
> same function in clk_set_rate_range() too so that we don't have
> to deal with recursive locking there.
Sweet, done.
>> kfree(clk);
>> }
>>
>
Thanks,
Tomeu
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