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Date:   Fri, 30 Apr 2021 18:58:16 +0100
From:   Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To:     Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
CC:     <linuxarm@huawei.com>, <mauro.chehab@huawei.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Hugues Fruchet <hugues.fruchet@st.com>,
        "Mauro Carvalho Chehab" <mchehab@kernel.org>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <linux-media@vger.kernel.org>,
        <linux-stm32@st-md-mailman.stormreply.com>
Subject: Re: [PATCH v4 73/79] media: stm32: use pm_runtime_resume_and_get()
Message-ID: <20210430185816.00000ef5@Huawei.com>
In-Reply-To: <cd918677e36e89196670cacd7027569e741f7d98.1619621413.git.mchehab+huawei@kernel.org>
References: <cover.1619621413.git.mchehab+huawei@kernel.org>
        <cd918677e36e89196670cacd7027569e741f7d98.1619621413.git.mchehab+huawei@kernel.org>
Organization: Huawei Technologies Research and Development (UK) Ltd.
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On Wed, 28 Apr 2021 16:52:34 +0200
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> wrote:

> Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> added pm_runtime_resume_and_get() in order to automatically handle
> dev->power.usage_count decrement on errors.
> 
> Use the new API, in order to cleanup the error check logic.
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> ---
>  drivers/media/platform/stm32/stm32-dcmi.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
> index bbcc2254fa2e..5f4e1db8cfcd 100644
> --- a/drivers/media/platform/stm32/stm32-dcmi.c
> +++ b/drivers/media/platform/stm32/stm32-dcmi.c
> @@ -723,11 +723,11 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	u32 val = 0;
>  	int ret;
>  
> -	ret = pm_runtime_get_sync(dcmi->dev);
> +	ret = pm_runtime_resume_and_get(dcmi->dev);
>  	if (ret < 0) {
>  		dev_err(dcmi->dev, "%s: Failed to start streaming, cannot get sync (%d)\n",
>  			__func__, ret);
> -		goto err_pm_put;
> +		goto err_unlock;

maybe err_unlocked; to indicate the lock isn't held.  This briefly confused me.

>  	}
>  
>  	ret = media_pipeline_start(&dcmi->vdev->entity, &dcmi->pipeline);
> @@ -848,6 +848,7 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count)
>  
>  err_pm_put:
>  	pm_runtime_put(dcmi->dev);
> +err_unlock:
>  	spin_lock_irq(&dcmi->irqlock);
>  	/*
>  	 * Return all buffers to vb2 in QUEUED state.