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From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: <linuxarm@huawei.com>, <mauro.chehab@huawei.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Sylwester Nawrocki <s.nawrocki@samsung.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, <linux-media@vger.kernel.org>,
	<linux-samsung-soc@vger.kernel.org>
Subject: Re: [PATCH 23/25] media: exynos4-is: fix pm_runtime_get_sync() usage count
Date: Wed, 5 May 2021 13:20:16 +0100	[thread overview]
Message-ID: <20210505132016.000078b5@Huawei.com> (raw)
In-Reply-To: <f03a865ec3f35c995231121b981877fe2a8587b2.1620207353.git.mchehab+huawei@kernel.org>

On Wed, 5 May 2021 11:42:13 +0200
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> wrote:

> The pm_runtime_get_sync() internally increments the
> dev->power.usage_count without decrementing it, even on errors.
> 
> On some places, this is ok, but on others the usage count
> ended being unbalanced on failures.
> 
> Replace it by the new pm_runtime_resume_and_get(), introduced by:
> commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> in order to properly decrement the usage counter, avoiding
> a potential PM usage counter leak.
> 
> As a bonus, such function always return zero on success. So,
> some code can be simplified.
> 
> Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Might be nice to call out the two odd cases below.

> diff --git a/drivers/media/platform/exynos4-is/mipi-csis.c b/drivers/media/platform/exynos4-is/mipi-csis.c
> index 1aac167abb17..ebf39c856894 100644
> --- a/drivers/media/platform/exynos4-is/mipi-csis.c
> +++ b/drivers/media/platform/exynos4-is/mipi-csis.c
> @@ -494,7 +494,7 @@ static int s5pcsis_s_power(struct v4l2_subdev *sd, int on)
>  	struct device *dev = &state->pdev->dev;
>  
>  	if (on)
> -		return pm_runtime_get_sync(dev);
> +		return pm_runtime_resume_and_get(dev);
>  
>  	return pm_runtime_put_sync(dev);
>  }
> @@ -509,11 +509,9 @@ static int s5pcsis_s_stream(struct v4l2_subdev *sd, int enable)
>  
>  	if (enable) {
>  		s5pcsis_clear_counters(state);
> -		ret = pm_runtime_get_sync(&state->pdev->dev);
> -		if (ret && ret != 1) {
Perhaps add something to the description on this less common case?

> -			pm_runtime_put_noidle(&state->pdev->dev);
> +		ret = pm_runtime_resume_and_get(&state->pdev->dev);
> +		if (ret < 0)
>  			return ret;
> -		}
>  	}
>  
>  	mutex_lock(&state->lock);
> @@ -535,7 +533,7 @@ static int s5pcsis_s_stream(struct v4l2_subdev *sd, int enable)
>  	if (!enable)
>  		pm_runtime_put(&state->pdev->dev);
>  
> -	return ret == 1 ? 0 : ret;
> +	return ret;
>  }
>  
>  static int s5pcsis_enum_mbus_code(struct v4l2_subdev *sd,


  reply	other threads:[~2021-05-05 12:22 UTC|newest]

Thread overview: 73+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-05  9:41 [PATCH 00/25] Fix some PM runtime issues at the media subsystem Mauro Carvalho Chehab
2021-05-05  9:41 ` [PATCH 01/25] staging: media: rkvdec: fix pm_runtime_get_sync() usage count Mauro Carvalho Chehab
2021-05-05 12:23   ` Jonathan Cameron
2021-05-05  9:41 ` [PATCH 02/25] staging: media: imx7-mipi-csis: " Mauro Carvalho Chehab
2021-05-05 11:06   ` Jonathan Cameron
2021-05-05 11:17     ` Mauro Carvalho Chehab
2021-05-05 13:56     ` Rui Miguel Silva
2021-05-05 14:23       ` Mauro Carvalho Chehab
2021-05-05  9:41 ` [PATCH 03/25] media: venus: Rework error fail recover logic Mauro Carvalho Chehab
2021-05-05 11:05   ` Jonathan Cameron
2021-05-05  9:41 ` [PATCH 04/25] media: s5p_cec: decrement usage count if disabled Mauro Carvalho Chehab
2021-05-05 12:24   ` Jonathan Cameron
2021-05-05  9:41 ` [PATCH 05/25] media: i2c: ccs-core: return the right error code at suspend Mauro Carvalho Chehab
2021-05-05 12:24   ` Jonathan Cameron
2021-05-05 12:51   ` Sakari Ailus
2021-05-05  9:41 ` [PATCH 06/25] media: i2c: imx334: fix the pm runtime get logic Mauro Carvalho Chehab
2021-05-05 11:10   ` Jonathan Cameron
2021-05-05 11:24     ` Mauro Carvalho Chehab
2021-05-05 12:26       ` Jonathan Cameron
2021-05-05  9:41 ` [PATCH 07/25] media: exynos-gsc: don't resume at remove time Mauro Carvalho Chehab
2021-05-05 12:27   ` Jonathan Cameron
2021-05-05  9:41 ` [PATCH 08/25] media: atmel: properly get pm_runtime Mauro Carvalho Chehab
2021-05-05 12:08   ` Jonathan Cameron
2021-06-10  9:04     ` Eugen.Hristev
2021-06-10  9:38       ` Mauro Carvalho Chehab
2021-06-10 12:00         ` Eugen.Hristev
2021-06-16  8:03           ` Mauro Carvalho Chehab
2021-09-06  8:03           ` Mauro Carvalho Chehab
2021-09-06  8:13             ` Eugen.Hristev
2021-09-13 10:26               ` Eugen.Hristev
2021-05-05  9:41 ` [PATCH 09/25] media: hantro: do a PM resume earlier Mauro Carvalho Chehab
2021-05-05 11:34   ` Jonathan Cameron
2021-05-05 13:22   ` Ezequiel Garcia
2021-05-05 13:46     ` Mauro Carvalho Chehab
2021-05-05 14:01       ` Ezequiel Garcia
2021-05-05 14:15         ` Mauro Carvalho Chehab
2021-05-05  9:42 ` [PATCH 10/25] media: marvel-ccic: fix some issues when getting pm_runtime Mauro Carvalho Chehab
2021-05-05  9:42 ` [PATCH 11/25] media: mdk-mdp: fix pm_runtime_get_sync() usage count Mauro Carvalho Chehab
2021-05-05  9:42 ` [PATCH 12/25] media: rcar_fdp1: simplify error check logic at fdp_open() Mauro Carvalho Chehab
2021-05-05  9:48   ` Sergei Shtylyov
2021-05-05  9:42 ` [PATCH 13/25] media: rcar_fdp1: fix pm_runtime_get_sync() usage count Mauro Carvalho Chehab
2021-05-05 12:31   ` Jonathan Cameron
2021-05-05  9:42 ` [PATCH 14/25] media: renesas-ceu: Properly check for PM errors Mauro Carvalho Chehab
2021-05-05  9:56   ` Jacopo Mondi
2021-05-05  9:42 ` [PATCH 15/25] media: s5p: fix pm_runtime_get_sync() usage count Mauro Carvalho Chehab
2021-05-05 12:31   ` Jonathan Cameron
2021-05-05  9:42 ` [PATCH 16/25] media: am437x: " Mauro Carvalho Chehab
2021-05-05 12:32   ` Jonathan Cameron
2021-05-08 13:01   ` Lad, Prabhakar
2021-05-05  9:42 ` [PATCH 17/25] media: sh_vou: " Mauro Carvalho Chehab
2021-05-05  9:42 ` [PATCH 18/25] media: mtk-vcodec: fix PM runtime get logic Mauro Carvalho Chehab
2021-05-05 12:32   ` Jonathan Cameron
2021-05-05  9:42 ` [PATCH 19/25] media: s5p-jpeg: fix pm_runtime_get_sync() usage count Mauro Carvalho Chehab
2021-05-05 12:33   ` Jonathan Cameron
2021-05-05  9:42 ` [PATCH 20/25] media: sti/delta: use pm_runtime_resume_and_get() Mauro Carvalho Chehab
2021-05-05 12:01   ` Jonathan Cameron
2021-05-05 12:33     ` Jonathan Cameron
2021-05-05  9:42 ` [PATCH 21/25] media: sunxi: fix pm_runtime_get_sync() usage count Mauro Carvalho Chehab
2021-05-05  9:42 ` [PATCH 22/25] media: sti/bdisp: " Mauro Carvalho Chehab
2021-05-05 12:34   ` Jonathan Cameron
2021-05-05  9:42 ` [PATCH 23/25] media: exynos4-is: " Mauro Carvalho Chehab
2021-05-05 12:20   ` Jonathan Cameron [this message]
2021-05-05  9:42 ` [PATCH 24/25] media: exynos-gsc: " Mauro Carvalho Chehab
2021-05-05 12:34   ` Jonathan Cameron
2021-05-05  9:42 ` [PATCH 25/25] media: i2c: ccs-core: " Mauro Carvalho Chehab
2021-05-05 10:34   ` Sakari Ailus
2021-05-05 10:57     ` Mauro Carvalho Chehab
2021-05-05 10:58       ` Mauro Carvalho Chehab
2021-05-05 12:35         ` Jonathan Cameron
2021-05-05 14:06           ` Mauro Carvalho Chehab
2021-05-05 16:36             ` Jonathan Cameron
2021-05-05 11:02       ` Sakari Ailus
2021-05-06 15:11 ` [PATCH 00/25] Fix some PM runtime issues at the media subsystem Mauro Carvalho Chehab

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