diff mbox series

[v2,20/30] media: ov5647: Program mode only if it has changed

Message ID 20201104103622.595908-21-jacopo@jmondi.org (mailing list archive)
State New, archived
Headers show
Series media: ov5647: Support RaspberryPi Camera Module v1 | expand

Commit Message

Jacopo Mondi Nov. 4, 2020, 10:36 a.m. UTC
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.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
---
 drivers/media/i2c/ov5647.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

Comments

Dave Stevenson Nov. 4, 2020, 12:20 p.m. UTC | #1
Hi Jacopo

On Wed, 4 Nov 2020 at 10:37, Jacopo Mondi <jacopo@jmondi.org> 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.

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@jmondi.org>
> ---
>  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
>
Jacopo Mondi Nov. 4, 2020, 2:59 p.m. UTC | #2
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@jmondi.org> 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@jmondi.org>
> > ---
> >  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
> >
diff mbox series

Patch

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)