Hi Dave,
On Wed, Nov 04, 2020 at 12:20:26PM +0000, Dave Stevenson wrote:
> Hi Jacopo
>
> On Wed, 4 Nov 2020 at 10:37, Jacopo Mondi <jacopo@xxxxxxxxxx> 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.
>
> This patch is redundant as you've moved the power calls into s_stream,
> and you can't change mode whilst streaming.
You're probably right, but I don't think the reason it's because you
cannot s_ftm() while streaming, at least, not in the current
implementation because ov5647_set_pad_fmt() doesn't actually perform
any 'if (sensor->streaming) return -EBUSY;' and the core doesn't
protect you against this (as far I can tell there's no 'streaming
state' the core is aware of) Although the driver should probably reject
s_fmt() during streaming and that's something I should add in v3?
Anyway, you're right on this: the sensor gets powered on at every
s_stream() now, so whatever mode is requested, it has to be programmed
regardless.
Thanks!
j
>
> It made sense when s_power was independent, as s_power(1), set_mode,
> set_mode, set_mode, s_power(0) was valid and could result in the same
> register set being written multiple times for no gain.
>
> Dave
>
> > Signed-off-by: Jacopo Mondi <jacopo@xxxxxxxxxx>
> > ---
> > drivers/media/i2c/ov5647.c | 15 ++++++++++++++-
> > 1 file changed, 14 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/media/i2c/ov5647.c b/drivers/media/i2c/ov5647.c
> > index 21983af55c23f..6e500fb548c74 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;
> > const struct ov5647_mode *mode;
> > + const struct ov5647_mode *current_mode;
> > };
> >
> > static inline struct ov5647 *to_sensor(struct v4l2_subdev *sd)
> > @@ -755,6 +756,9 @@ static int ov5647_set_mode(struct v4l2_subdev *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;
> > @@ -781,6 +785,8 @@ static int ov5647_set_mode(struct v4l2_subdev *sd)
> > return ret;
> > }
> >
> > + sensor->current_mode = sensor->mode;
> > +
> > return 0;
> > }
> >
> > @@ -819,6 +825,7 @@ 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 |
> > @@ -830,7 +837,13 @@ 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)
> > --
> > 2.29.1
> >
