Re: [PATCH] media: i2c: imx274: fix s_frame_interval runtime resume not requested

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Hi Eugen,

On Wed, Nov 17, 2021 at 05:40:09PM +0200, Eugen Hristev wrote:
> pm_runtime_resume_and_get should be called when the s_frame_interval
> is called.
> 
> The driver will try to access device registers to configure VMAX, coarse
> time and exposure.
> 
> Currently if the runtime is not resumed, this fails:
>  # media-ctl -d /dev/media0 --set-v4l2 '"IMX274 1-001a":0[fmt:SRGGB10_1X10/3840x2
> 160@1/10]'
> 
> IMX274 1-001a: imx274_binning_goodness: ask 3840x2160, size 3840x2160, goodness 0
> IMX274 1-001a: imx274_binning_goodness: ask 3840x2160, size 1920x1080, goodness -3000
> IMX274 1-001a: imx274_binning_goodness: ask 3840x2160, size 1280x720, goodness -4000
> IMX274 1-001a: imx274_binning_goodness: ask 3840x2160, size 1280x540, goodness -4180
> IMX274 1-001a: __imx274_change_compose: selected 1x1 binning
> IMX274 1-001a: imx274_set_frame_interval: input frame interval = 1 / 10
> IMX274 1-001a: imx274_read_mbreg : addr 0x300e, val=0x1 (2 bytes)
> IMX274 1-001a: imx274_set_frame_interval : register SVR = 1
> IMX274 1-001a: imx274_read_mbreg : addr 0x30f6, val=0x6a8 (2 bytes)
> IMX274 1-001a: imx274_set_frame_interval : register HMAX = 1704
> IMX274 1-001a: imx274_set_frame_length : input length = 2112
> IMX274 1-001a: imx274_write_mbreg : i2c bulk write failed, 30f8 = 884 (3 bytes)
> IMX274 1-001a: imx274_set_frame_length error = -121
> IMX274 1-001a: imx274_set_frame_interval error = -121
> Unable to setup formats: Remote I/O error (121)
> 
> The device is not resumed thus the remote I/O error.
> 
> Setting the frame interval works at streaming time, because
> pm_runtime_resume_and_get is called at s_stream time before sensor setup.
> The failure happens when only the s_frame_interval is called separately
> independently on streaming time.
> 
> Fixes: ad97bc37426c ("media: i2c: imx274: Add IMX274 power on and off sequence"
> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> ---
>  drivers/media/i2c/imx274.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/media/i2c/imx274.c b/drivers/media/i2c/imx274.c
> index e89ef35a71c5..6e63fdcc5e46 100644
> --- a/drivers/media/i2c/imx274.c
> +++ b/drivers/media/i2c/imx274.c
> @@ -1420,6 +1420,10 @@ static int imx274_s_frame_interval(struct v4l2_subdev *sd,
>  	int min, max, def;
>  	int ret;
>  
> +	ret = pm_runtime_resume_and_get(&imx274->client->dev);
> +	if (ret < 0)
> +		return ret;
> +
>  	mutex_lock(&imx274->lock);
>  	ret = imx274_set_frame_interval(imx274, fi->interval);
>  
> @@ -1451,6 +1455,7 @@ static int imx274_s_frame_interval(struct v4l2_subdev *sd,
>  
>  unlock:
>  	mutex_unlock(&imx274->lock);
> +	pm_runtime_put(&imx274->client->dev);
>  
>  	return ret;
>  }

If the device is powered off in the end, could you instead not power it on
in the first place? I.e. see how this works for the s_ctrl() callback.

-- 
Kind regards,

Sakari Ailus