linux-kernel - Re: [PATCH v3 3/3] clk: qcom: Add Global Clock controller (GCC) driver for SC7180

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Message-ID: <d17dad3d-d32c-b71c-0e56-d15cb246f742@codeaurora.org>
Date:   Wed, 9 Oct 2019 14:49:39 +0530
From:   Taniya Das <tdas@...eaurora.org>
To:     Stephen Boyd <sboyd@...nel.org>,
        Michael Turquette <mturquette@...libre.com>, robh+dt@...nel.org
Cc:     David Brown <david.brown@...aro.org>,
        Rajendra Nayak <rnayak@...eaurora.org>,
        linux-arm-msm@...r.kernel.org, linux-soc@...r.kernel.org,
        linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org
Subject: Re: [PATCH v3 3/3] clk: qcom: Add Global Clock controller (GCC)
 driver for SC7180

Hi Stephen,

On 10/5/2019 4:50 AM, Stephen Boyd wrote:
> Quoting Taniya Das (2019-10-04 10:39:31)
>> Hi Stephen,
>>
>> On 10/3/2019 9:31 PM, Stephen Boyd wrote:
>>> Quoting Taniya Das (2019-10-03 03:31:15)
>>>> Hi Stephen,
>>>>
>>>> On 10/1/2019 8:08 PM, Stephen Boyd wrote:
>>>>>
>>>>> Why do you want to keep them critical and registered? I'm suggesting
>>>>> that any clk that is marked critical and doesn't have a parent should
>>>>> instead become a register write in probe to turn the clk on.
>>>>>
>>>> Sure, let me do a one-time enable from probe for the clocks which
>>>> doesn't have a parent.
>>>> But I would now have to educate the clients of these clocks to remove
>>>> using them.
>>>>
>>>
>>> If anyone is using these clks we can return NULL from the provider for
>>> the specifier so that we indicate there isn't support for them in the
>>> kernel. At least I hope that code path still works given all the recent
>>> changes to clk_get().
>>>
>>
>> Could you please confirm if you are referring to update the below?
> 
> I wasn't suggesting that explicitly but sure. Something like this would
> be necessary to make clk_get() pass back a NULL pointer to the caller.
> Does everything keep working with this change?
> 

Even if I pass back NULL, I don't see it working. Please suggest how to 
take it forward.

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