Re: Question about suspend/resume clock handling in dwc3-of-simple.c

From: Felipe Balbi
Date: Tue Sep 13 2016 - 10:06:39 EST



Hi,

Guenter Roeck <linux@xxxxxxxxxxxx> writes:
> On 09/12/2016 10:35 PM, Felipe Balbi wrote:
>>
>> Hi,
>>
>> Guenter Roeck <linux@xxxxxxxxxxxx> writes:
>>>>> Should it be clk_disable_unprepare(), or maybe something like the
>>>>> following
>>>>>
>>>>> if (!pm_runtime_status_suspended(dev))
>>>>> clk_disable_unprepare();
>>>>> else
>>>>> clk_unprepare();
>>>>
>>>> I'm not sure how balanced those calls are, yeah. I don't have HW to test
>>>> PM with. But note that as it is, there is no actual runtime PM support,
>>>> so clk_disable_unprepare() will always be necessary.
>>>>
>>>> Perhaps we will find further issues when someone tries to use runtime PM
>>>> with dwc3-of-simple. ;-)
>>>>
>>>
>>> We are working on code derived from it, so unless I can convince the author
>>> that he can not just use clk_unprepare() I suspect we'll hit the problem.
>>> If so, I'll let you know.
>>
>> Are you sending that upstream? Depending on your requirements, it might
>> be easier to patch dwc3-of-simple.c then adding yet another glue layer :-)
>>
> Yes. It will be a glue layer. So far that looks like the cleanest solution.

fair enough, take your time ;-)

--
balbi