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Subject: Re: [PATCH] spi: tegra20-slink: Fix runtime PM imbalance on error
From:   Jon Hunter <jonathanh@nvidia.com>
To:     Andy Shevchenko <andy.shevchenko@gmail.com>,
        Dinghao Liu <dinghao.liu@zju.edu.cn>
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Date:   Thu, 21 May 2020 09:46:48 +0100
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On 21/05/2020 09:38, Jon Hunter wrote:
> 
> On 21/05/2020 09:04, Andy Shevchenko wrote:
>> On Thu, May 21, 2020 at 10:50 AM Dinghao Liu <dinghao.liu@zju.edu.cn> wrote:
>>>
>>> pm_runtime_get_sync() increments the runtime PM usage counter even
>>> when it returns an error code. Thus a pairing decrement is needed on
>>> the error handling path to keep the counter balanced.
>>
>> ...
>>
>>>         ret = pm_runtime_get_sync(&pdev->dev);
>>>         if (ret < 0) {
>>>                 dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
>>
>>> +               pm_runtime_put(&pdev->dev);
>>
>> For all your patches, please, double check what you are proposing.
>>
>> Here, I believe, the correct one will be _put_noidle().
>>
>> AFAIU you are not supposed to actually suspend the device in case of error.
>> But I might be mistaken, thus see above.
>>
>>>                 goto exit_pm_disable;
>>>         }
> 
> 
> Is there any reason why this is not handled in pm_runtime_get itself?

Ah I see a response from Rafael here:
https://lkml.org/lkml/2020/5/20/1100

OK so this is intentional and needs to be fixed.

Jon

-- 
nvpublic