linux-kernel - Re: [PATCHv2 2/6] thermal: exynos: Reorder the gpu clock initialization for exynos5420 SoC

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Message-ID: <023e6b0c-26a8-1563-1861-9a5cfe715c1f@linaro.org>
Date:   Sat, 21 May 2022 16:20:23 +0200
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     Anand Moon <linux.amoon@...il.com>
Cc:     Bartlomiej Zolnierkiewicz <bzolnier@...il.com>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Amit Kucheria <amitk@...nel.org>,
        Zhang Rui <rui.zhang@...el.com>,
        Alim Akhtar <alim.akhtar@...sung.com>,
        Linux PM list <linux-pm@...r.kernel.org>,
        linux-samsung-soc@...r.kernel.org,
        linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>,
        Linux Kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCHv2 2/6] thermal: exynos: Reorder the gpu clock
 initialization for exynos5420 SoC

On 21/05/2022 11:51, Anand Moon wrote:
> Hi Krzysztof,
> 
> On Wed, 18 May 2022 at 12:58, Krzysztof Kozlowski
> <krzysztof.kozlowski@...aro.org> wrote:
>>
>> On 17/05/2022 20:43, Anand Moon wrote:
>>> Hi Krzysztof,
>>>
>>> On Sun, 15 May 2022 at 15:11, Krzysztof Kozlowski
>>> <krzysztof.kozlowski@...aro.org> wrote:
>>>>
>>>> On 15/05/2022 08:41, Anand Moon wrote:
>>>>> Reorder the tmu_gpu clock initialization for exynos5422 SoC.
>>>>
>>>> Why?
>>> It just code reorder
>>
>> I know what it is. I asked why. The answer in English to question "Why"
>> is starting with "Because".
>>
>> You repeated again the argument what are you doing to my question "Why
>> are you doing it".
>>
> tmu_triminfo_apbif is not a core driver to all the Exynos SOC board
> it is only used by the Exynos542x SOC family
> 
> If we look into the original code its place in between
> the devm_clk_get(data->clk) and clk_prepare(data->clk)
> after this change, the code is in the correct order of initialization
> of the clock.

What was wrong with original order? You still did not explain it.

> 
>> It was the same before, many, many times. It's a waste of reviewers
>> time, because you receive a review and you do not implement the feedback.
>>
>>>>
>>>>>
>>>>> Cc: Bartlomiej Zolnierkiewicz <bzolnier@...il.com>
>>>>> Signed-off-by: Anand Moon <linux.amoon@...il.com>
>>>>> ---
>>>>> v1: split the changes and improve the commit messages
>>>>> ---
>>>>>  drivers/thermal/samsung/exynos_tmu.c | 43 ++++++++++++++--------------
>>>>>  1 file changed, 21 insertions(+), 22 deletions(-)
>>>>>
>>>>> diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
>>>>> index 75b3afadb5be..1ef90dc52c08 100644
>>>>> --- a/drivers/thermal/samsung/exynos_tmu.c
>>>>> +++ b/drivers/thermal/samsung/exynos_tmu.c
>>>>> @@ -1044,42 +1044,41 @@ static int exynos_tmu_probe(struct platform_device *pdev)
>>>>>               dev_err(&pdev->dev, "Failed to get clock\n");
>>>>>               ret = PTR_ERR(data->clk);
>>>>>               goto err_sensor;
>>>>> -     }
>>>>> -
>>>>> -     data->clk_sec = devm_clk_get(&pdev->dev, "tmu_triminfo_apbif");
>>>>> -     if (IS_ERR(data->clk_sec)) {
>>>>> -             if (data->soc == SOC_ARCH_EXYNOS5420_TRIMINFO) {
>>>>> -                     dev_err(&pdev->dev, "Failed to get triminfo clock\n");
>>>>> -                     ret = PTR_ERR(data->clk_sec);
>>>>> -                     goto err_sensor;
>>>>> -             }
>>>>>       } else {
>>>>> -             ret = clk_prepare_enable(data->clk_sec);
>>>>> +             ret = clk_prepare_enable(data->clk);
>>>>
>>>> This looks a bit odd. The clock was before taken unconditionally, not
>>>> within "else" branch...
>>>
>>> The whole *clk_sec*  ie tmu_triminfo_apbif clock enable is being moved
>>> down to the switch case.
>>> tmu_triminfo_apbif  clock is not used by Exynos4412 and Exynos5433 and
>>> Exynos7 SoC.
>>
>> This is not the answer. Why are you preparing data->clk within else{}
>> branch?
>>
> After cleanly applying the patches I see the below changes.
> if you want me to remove the else part below and keep
> the original code I am ok.
> 
>         data->clk = devm_clk_get(&pdev->dev, "tmu_apbif");
>         if (IS_ERR(data->clk)) {
>                 dev_err(&pdev->dev, "Failed to get clock\n");
>                 ret = PTR_ERR(data->clk);
>                 goto err_sensor;
>         } else {
>                 ret = clk_prepare_enable(data->clk);

Which is wrong and does not make any sense. This is third question - why
the main clock is prepared within 'else' branch?

Best regards,
Krzysztof