Re: [RFC PATCH 6/7] mmc: sdhci-omap: Add OMAP SDHCI driver

From: Adrian Hunter
Date: Thu Aug 17 2017 - 04:30:12 EST


On 17/08/17 10:59, Kishon Vijay Abraham I wrote:
> Hi Adrian,
>
> On Thursday 17 August 2017 12:13 PM, Adrian Hunter wrote:
>> On 17/08/17 08:57, Kishon Vijay Abraham I wrote:
>>> Hi Adrian,
>>>
>>> On Tuesday 15 August 2017 01:52 PM, Adrian Hunter wrote:
>>>> On 07/08/17 19:01, Kishon Vijay Abraham I wrote:

<SNIP>

>>>>> + pm_runtime_enable(dev);
>>>>> + ret = pm_runtime_get_sync(dev);
>>>>
>>>> What are you trying to do with runtime pm? There don't seem to be any pm
>>>> callbacks, so does this do anything?
>>>
>>> yeah, pm_runtime_get_sync enables the functional clock and also configures the
>>> SYSCONFIG regiters present in the controller. It gets the details for
>>> configuring those from arch/arm/mach-omap2/omap_hwmod_*
>>
>> You mean it will do those things when you add the callbacks? I would prefer
>> you leave out runtime pm until you can add the callbacks as well.
>
> No. Generally in callbacks, 'optional' functional clocks are enabled. But main
> functional clock and interface clocks are enabled in pm_runtime_get_sync.
> Without pm_runtime_get_sync, we won't be able to access controller registers.

So that is done by the pm domain? Please add comments to the code to explain.