linux-kernel - Re: [PATCH] media: ov5640: Update last busy timestamp to reset autosuspend timer

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Message-ID: <20230114151906.gkgmhzpq64dhwouu@uno.localdomain>
Date:   Sat, 14 Jan 2023 16:19:06 +0100
From:   Jacopo Mondi <jacopo.mondi@...asonboard.com>
To:     Sakari Ailus <sakari.ailus@....fi>
Cc:     Andrey Skvortsov <andrej.skvortzov@...il.com>,
        Steve Longerbeam <slongerbeam@...il.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        linux-media@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] media: ov5640: Update last busy timestamp to reset
 autosuspend timer

Hi Sakari

On Sat, Jan 14, 2023 at 02:29:14PM +0200, Sakari Ailus wrote:
> Hi Andrey,
>
> On Sat, Jan 14, 2023 at 02:21:09PM +0300, Andrey Skvortsov wrote:
> > Otherwise autosuspend delay doesn't work and power is cut off
> > immediately as device is freed.
> >
> > Signed-off-by: Andrey Skvortsov <andrej.skvortzov@...il.com>
> > ---
> >  drivers/media/i2c/ov5640.c | 9 ++++++++-
> >  1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> > index ac35350..f71c0f7 100644
> > --- a/drivers/media/i2c/ov5640.c
> > +++ b/drivers/media/i2c/ov5640.c
> > @@ -1238,6 +1238,7 @@ static int ov5640_write_reg(struct ov5640_dev *sensor, u16 reg, u8 val)
> >  		return ret;
> >  	}
> >
> > +	pm_runtime_mark_last_busy(&sensor->i2c_client->dev);
> >  	return 0;
> >  }
> >
> > @@ -1305,6 +1306,7 @@ static int ov5640_read_reg(struct ov5640_dev *sensor, u16 reg, u8 *val)
> >  	}
> >
> >  	*val = buf[0];
> > +	pm_runtime_mark_last_busy(&sensor->i2c_client->dev);
>
> I wouldn't add these calls to register accesses. It's generally relevant
> with autosuspend_put().
>
> The rest seems fine to me.
>

Does it mean the same should be done for the all the sensor drivers that
use autosuspend ? I count 8 of them, not a huge number.

> >  	return 0;
> >  }
> >
> > @@ -3615,6 +3617,7 @@ static int ov5640_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
> >  		break;
> >  	}
> >
> > +	pm_runtime_mark_last_busy(&sensor->i2c_client->dev);
> >  	pm_runtime_put_autosuspend(&sensor->i2c_client->dev);
> >
> >  	return 0;
> > @@ -3702,6 +3705,7 @@ static int ov5640_s_ctrl(struct v4l2_ctrl *ctrl)
> >  		break;
> >  	}
> >
> > +	pm_runtime_mark_last_busy(&sensor->i2c_client->dev);
> >  	pm_runtime_put_autosuspend(&sensor->i2c_client->dev);
> >
> >  	return ret;
> > @@ -4034,8 +4038,10 @@ static int ov5640_s_stream(struct v4l2_subdev *sd, int enable)
> >  out:
> >  	mutex_unlock(&sensor->lock);
> >
> > -	if (!enable || ret)
> > +	if (!enable || ret) {
> > +		pm_runtime_mark_last_busy(&sensor->i2c_client->dev);
> >  		pm_runtime_put_autosuspend(&sensor->i2c_client->dev);
> > +	}
> >
> >  	return ret;
> >  }
> > @@ -4203,6 +4209,7 @@ static int ov5640_probe(struct i2c_client *client)
> >
> >  	pm_runtime_set_autosuspend_delay(dev, 1000);
> >  	pm_runtime_use_autosuspend(dev);
> > +	pm_runtime_mark_last_busy(dev);
> >  	pm_runtime_put_autosuspend(dev);
> >
> >  	return 0;
>
> --
> Kind regards,
>
> Sakari Ailus