linux-kernel - Re: [PATCH v4 58/79] media: sti/hva: use pm_runtime_resume_and

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Date:   Fri, 30 Apr 2021 18:35:03 +0100
From:   Jonathan Cameron <Jonathan.Cameron@...wei.com>
To:     Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
CC:     <linuxarm@...wei.com>, <mauro.chehab@...wei.com>,
        Jean-Christophe Trotin <jean-christophe.trotin@...com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        <linux-kernel@...r.kernel.org>, <linux-media@...r.kernel.org>
Subject: Re: [PATCH v4 58/79] media: sti/hva: use
 pm_runtime_resume_and_get()

On Wed, 28 Apr 2021 16:52:19 +0200
Mauro Carvalho Chehab <mchehab+huawei@...nel.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.
> 
> While the hva driver does it right, there are lots of errors
> on other drivers due to its misusage. So, let's change
> this driver to also use pm_runtime_resume_and_get(), as we're
> doing similar changes all over the media subsystem.
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
Bit of a fiddly one, but looks right to me.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@...wei.com>

> ---
>  drivers/media/platform/sti/hva/hva-hw.c | 17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/media/platform/sti/hva/hva-hw.c b/drivers/media/platform/sti/hva/hva-hw.c
> index f59811e27f51..77b8bfa5e0c5 100644
> --- a/drivers/media/platform/sti/hva/hva-hw.c
> +++ b/drivers/media/platform/sti/hva/hva-hw.c
> @@ -270,9 +270,8 @@ static unsigned long int hva_hw_get_ip_version(struct hva_dev *hva)
>  	struct device *dev = hva_to_dev(hva);
>  	unsigned long int version;
>  
> -	if (pm_runtime_get_sync(dev) < 0) {
> +	if (pm_runtime_resume_and_get(dev) < 0) {
>  		dev_err(dev, "%s     failed to get pm_runtime\n", HVA_PREFIX);
> -		pm_runtime_put_noidle(dev);
>  		mutex_unlock(&hva->protect_mutex);
>  		return -EFAULT;
>  	}
> @@ -386,10 +385,10 @@ int hva_hw_probe(struct platform_device *pdev, struct hva_dev *hva)
>  	pm_runtime_set_suspended(dev);
>  	pm_runtime_enable(dev);
>  
> -	ret = pm_runtime_get_sync(dev);
> +	ret = pm_runtime_resume_and_get(dev);
>  	if (ret < 0) {
>  		dev_err(dev, "%s     failed to set PM\n", HVA_PREFIX);
> -		goto err_pm;
> +		goto err_clk;
>  	}
>  
>  	/* check IP hardware version */
> @@ -462,6 +461,7 @@ int hva_hw_execute_task(struct hva_ctx *ctx, enum hva_hw_cmd_type cmd,
>  	u8 client_id = ctx->id;
>  	int ret;
>  	u32 reg = 0;
> +	bool got_pm = false;
>  
>  	mutex_lock(&hva->protect_mutex);
>  
> @@ -469,12 +469,13 @@ int hva_hw_execute_task(struct hva_ctx *ctx, enum hva_hw_cmd_type cmd,
>  	enable_irq(hva->irq_its);
>  	enable_irq(hva->irq_err);
>  
> -	if (pm_runtime_get_sync(dev) < 0) {
> +	if (pm_runtime_resume_and_get(dev) < 0) {
>  		dev_err(dev, "%s     failed to get pm_runtime\n", ctx->name);
>  		ctx->sys_errors++;
>  		ret = -EFAULT;
>  		goto out;
>  	}
> +	got_pm = true;
>  
>  	reg = readl_relaxed(hva->regs + HVA_HIF_REG_CLK_GATING);
>  	switch (cmd) {
> @@ -537,7 +538,8 @@ int hva_hw_execute_task(struct hva_ctx *ctx, enum hva_hw_cmd_type cmd,
>  		dev_dbg(dev, "%s     unknown command 0x%x\n", ctx->name, cmd);
>  	}
>  
> -	pm_runtime_put_autosuspend(dev);
> +	if (got_pm)
> +		pm_runtime_put_autosuspend(dev);
>  	mutex_unlock(&hva->protect_mutex);
>  
>  	return ret;
> @@ -553,9 +555,8 @@ void hva_hw_dump_regs(struct hva_dev *hva, struct seq_file *s)
>  
>  	mutex_lock(&hva->protect_mutex);
>  
> -	if (pm_runtime_get_sync(dev) < 0) {
> +	if (pm_runtime_resume_and_get(dev) < 0) {
>  		seq_puts(s, "Cannot wake up IP\n");
> -		pm_runtime_put_noidle(dev);
>  		mutex_unlock(&hva->protect_mutex);
>  		return;
>  	}