Re: [PATCH 20/25] media: ov5647: Program mode only if it has changed

[Jacopo Mondi <jacopo@jmondi.org>]

Hi Dafna,

On Mon, Jun 29, 2020 at 07:48:16PM +0200, Dafna Hirschfeld wrote:
>
>
> On 23.06.20 18:55, Jacopo Mondi wrote:
> > Store in the driver structure a pointer to the currently applied mode
> > and program a new one at s_stream(1) time only if it has changed.
>
> Hi,
> I think this can be more readably implemented with a 'is_streaming' boolean
> field.

How would you like to use an 'is_streaming' flag to decide if the
sensor mode has to be updated ?

Thanks
   j


>
> Thanks,
> Dafna
>
> >
> > Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
> > ---
> >   drivers/media/i2c/ov5647.c | 16 +++++++++++++++-
> >   1 file changed, 15 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/media/i2c/ov5647.c b/drivers/media/i2c/ov5647.c
> > index 39e320f321bd8..ac114269e1c73 100644
> > --- a/drivers/media/i2c/ov5647.c
> > +++ b/drivers/media/i2c/ov5647.c
> > @@ -96,6 +96,7 @@ struct ov5647 {
> >   	bool				clock_ncont;
> >   	struct v4l2_ctrl_handler	ctrls;
> >   	struct ov5647_mode		*mode;
> > +	struct ov5647_mode		*current_mode;
> >   };
> >   static inline struct ov5647 *to_sensor(struct v4l2_subdev *sd)
> > @@ -750,9 +751,13 @@ static int ov5647_set_virtual_channel(struct v4l2_subdev *sd, int channel)
> >   static int ov5647_set_mode(struct v4l2_subdev *sd)
> >   {
> >   	struct i2c_client *client = v4l2_get_subdevdata(sd);
> > +	struct ov5647 *sensor = to_sensor(sd);
> >   	u8 resetval, rdval;
> >   	int ret;
> > +	if (sensor->mode == sensor->current_mode)
> > +		return 0;
> > +
> >   	ret = ov5647_read(sd, OV5647_SW_STANDBY, &rdval);
> >   	if (ret < 0)
> >   		return ret;
> > @@ -778,6 +783,8 @@ static int ov5647_set_mode(struct v4l2_subdev *sd)
> >   			return ret;
> >   	}
> > +	sensor->current_mode = sensor->mode;
> > +
> >   	return 0;
> >   }
> > @@ -816,6 +823,7 @@ static int ov5647_stream_on(struct v4l2_subdev *sd)
> >   static int ov5647_stream_off(struct v4l2_subdev *sd)
> >   {
> > +	struct ov5647 *sensor = to_sensor(sd);
> >   	int ret;
> >   	ret = ov5647_write(sd, OV5647_REG_MIPI_CTRL00, MIPI_CTRL00_CLOCK_LANE_GATE |
> > @@ -827,7 +835,13 @@ static int ov5647_stream_off(struct v4l2_subdev *sd)
> >   	if (ret < 0)
> >   		return ret;
> > -	return ov5647_write(sd, OV5640_REG_PAD_OUT, 0x01);
> > +	ret = ov5647_write(sd, OV5640_REG_PAD_OUT, 0x01);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	sensor->current_mode = NULL;
> > +
> > +	return 0;
> >   }
> >   static int set_sw_standby(struct v4l2_subdev *sd, bool standby)
> >