linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: <linuxarm@huawei.com>, <mauro.chehab@huawei.com>,
	"Paul J. Murphy" <paul.j.murphy@intel.com>,
	Daniele Alessandrelli <daniele.alessandrelli@intel.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	<linux-kernel@vger.kernel.org>, <linux-media@vger.kernel.org>,
	Dan Carpenter <dan.carpenter@oracle.com>
Subject: Re: [PATCH 06/25] media: i2c: imx334: fix the pm runtime get logic
Date: Wed, 5 May 2021 12:10:40 +0100	[thread overview]
Message-ID: <20210505121040.00002094@Huawei.com> (raw)
In-Reply-To: <9552f3daece8bec6869b518410b2998c3fc0a1fc.1620207353.git.mchehab+huawei@kernel.org>

On Wed, 5 May 2021 11:41:56 +0200
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> wrote:

> The PM runtime get logic is currently broken, as it checks if
> ret is zero instead of checking if it is an error code,
> as reported by Dan Carpenter.
> 
> While here, use the pm_runtime_resume_and_get() as added by:
> 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. As a bonus, such function
> always return zero on success.
> 
> It should also be noticed that a fail of pm_runtime_get_sync() would
> potentially result in a spurious runtime_suspend(), instead of
> using pm_runtime_put_noidle().

Irony here is that pm_runtime_resume_and_get() returns <= 0 so with that
function change, you can stick with if (ret) and still be correct.

So only one of the two changes is needed to fix the bug.

J
> 
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Reviewed-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> ---
>  drivers/media/i2c/imx334.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/i2c/imx334.c b/drivers/media/i2c/imx334.c
> index 047aa7658d21..23f28606e570 100644
> --- a/drivers/media/i2c/imx334.c
> +++ b/drivers/media/i2c/imx334.c
> @@ -717,9 +717,9 @@ static int imx334_set_stream(struct v4l2_subdev *sd, int enable)
>  	}
>  
>  	if (enable) {
> -		ret = pm_runtime_get_sync(imx334->dev);
> -		if (ret)
> -			goto error_power_off;
> +		ret = pm_runtime_resume_and_get(imx334->dev);
> +		if (ret < 0)
> +			goto error_unlock;
>  
>  		ret = imx334_start_streaming(imx334);
>  		if (ret)
> @@ -737,6 +737,7 @@ static int imx334_set_stream(struct v4l2_subdev *sd, int enable)
>  
>  error_power_off:
>  	pm_runtime_put(imx334->dev);
> +error_unlock:
>  	mutex_unlock(&imx334->mutex);
>  
>  	return ret;


  reply	other threads:[~2021-05-05 11:12 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 [this message]
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
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210505121040.00002094@Huawei.com \
    --to=jonathan.cameron@huawei.com \
    --cc=dan.carpenter@oracle.com \
    --cc=daniele.alessandrelli@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=linuxarm@huawei.com \
    --cc=mauro.chehab@huawei.com \
    --cc=mchehab+huawei@kernel.org \
    --cc=mchehab@kernel.org \
    --cc=paul.j.murphy@intel.com \
    --subject='Re: [PATCH 06/25] media: i2c: imx334: fix the pm runtime get logic' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).