Re: [PATCH v6 51/52] PM / devfreq: tegra30: Support interconnect and OPPs from device-tree

[Dmitry Osipenko]

01.11.2020 18:57, Chanwoo Choi пишет:
> On Mon, Nov 2, 2020 at 12:49 AM Dmitry Osipenko <digetx@xxxxxxxxx> wrote:
>>
>> 01.11.2020 18:44, Chanwoo Choi пишет:
>>>> OPP core will try to grab the clock reference for the table and it may
>>>> cause EPROBE_DEFER. Although, it shouldn't happen here because we have
>>>> devm_clk_get() before the get_opp_table(), hence seems the deferred
>>>> probe indeed shouldn't happen in this case.
>>> It is my missing point. If there, you're right.
>>> Could you provide the code point to check the clock reference on the OPP core?
>>
>> Please see it here:
>>
>> https://elixir.bootlin.com/linux/v5.10-rc1/source/drivers/opp/core.c#L1101
> 
> Thanks. It seems that if device tree node contains the any node,
> it is not EPROBE_DEFER because of just using "clk_get(dev, NULL)".
> 
> The patch[1] used the 'dev_err_probe' for getting the "emc" clock.
> Do you need to check it more?
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/commit/?h=devfreq-next&id=09d56d92ad25b58113f4ec677e9b1ac1e2c3072b

It should be safe to assume that the EPROBE_DEFER won't happen for
dev_pm_opp_get_opp_table(). I'll improve it in v7, thanks.