On Wed, Oct 22, 2014 at 5:28 PM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
> On 22 October 2014 17:09, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>> On Wed, Oct 22, 2014 at 5:01 PM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
>>>>>> +void keystone_pm_domain_attach_dev(struct device *dev)
>>>>>> {
>>>>>> + struct clk *clk;
>>>>>> int ret;
>>>>>> + int i = 0;
>>>>>>
>>>>>> dev_dbg(dev, "%s\n", __func__);
>>>>>>
>>>>>> - ret = pm_generic_runtime_suspend(dev);
>>>>>> - if (ret)
>>>>>> - return ret;
>>>>>> -
>>>>>> - ret = pm_clk_suspend(dev);
>>>>>> + ret = pm_clk_create(dev);
>>>>>> if (ret) {
>>>>>> - pm_generic_runtime_resume(dev);
>>>>>> - return ret;
>>>>>> + dev_err(dev, "pm_clk_create failed %d\n", ret);
>>>>>> + return;
>>>>>> + };
>>>>>> +
>>>>>> + while ((clk = of_clk_get(dev->of_node, i++)) && !IS_ERR(clk)) {
>>>>>> + ret = pm_clk_add_clk(dev, clk);
>>>>>> + if (ret) {
>>>>>> + dev_err(dev, "pm_clk_add_clk failed %d\n", ret);
>>>>>> + goto clk_err;
>>>>>> + };
>>>>>> }
>>>>>>
>>>>>> - return 0;
>>>>>> + if (!IS_ENABLED(CONFIG_PM_RUNTIME)) {
>>>>> Can we not okkup two seperate callbacks instead of above check ?
>>>>> I don't like this CONFIG check here. Its slightly better version of
>>>>> ifdef in middle of the code.
>>>>
>>>> I've found more-less similar comment on patch
>>>> "Re: [PATCH v3 1/3] power-domain: add power domain drivers for Rockchip platform"
>>>> https://lkml.org/lkml/2014/10/17/257
>>>>
>>>> So, Would you like me to create patch which will enable clocks in pm_clk_add/_clk()
>>>> in case !IS_ENABLED(CONFIG_PM_RUNTIME)
>>>
>>> I am wondering whether we actually should/could do this, no matter of
>>> CONFIG_PM_RUNTIME.
>>>
>>> Typically, for configurations that uses CONFIG_PM_RUNTIME, the PM
>>> clocks through pm_clk_suspend(), will be gated once the device becomes
>>> runtime PM suspended. Right?
>>
>> Doing it unconditionally means we'll have lots of unneeded clocks running
>> for a short while.
> As long as the pm_clk_add() is being invoked from the ->attach_dev()
> callback, we are in the probe path. Certainly we would like to have
> clocks enabled while probing, don't you think?
>
> If we wouldn't enable the clocks for CONFIG_PM_RUNTIME, when will
> those be enabled?
They will be enabled when the driver does
pm_runtime_enable(dev);
pm_runtime_get_sync(dev);
in its .probe() method.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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