Re: [PATCH v2 3/3] media: mt9m111: don't turn on the output while powering it

From: Laurent Pinchart
Date: Mon Sep 19 2022 - 09:00:46 EST


Hi Marco,

Thank you for the patch.

On Fri, Sep 16, 2022 at 03:57:13PM +0200, Marco Felsch wrote:
> Currently the .s_power() turn on/off the device and enables/disables the
> sensor output. This is wrong since it should only handle the power not
> not the sensor output behaviour. Enabling the sensor output should be
> part of the .s_stream() callback.
>
> Fix this by adding mt9m111_set_output() which gets called by the
> .s_stream() callback and remove the output register bits from
> mt9m111_resume/suspend.
>
> Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
> ---
> Changelog:
>
> v2:
> - new patch, replaces: "media: mt9m111: remove .s_power callback"
> ---
> drivers/media/i2c/mt9m111.c | 38 ++++++++++++++++++++++++++-----------
> 1 file changed, 27 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/media/i2c/mt9m111.c b/drivers/media/i2c/mt9m111.c
> index 8de93ab99cbc..2cc0b0da7636 100644
> --- a/drivers/media/i2c/mt9m111.c
> +++ b/drivers/media/i2c/mt9m111.c
> @@ -426,10 +426,25 @@ static int mt9m111_setup_geometry(struct mt9m111 *mt9m111, struct v4l2_rect *rec
> return ret;
> }
>
> -static int mt9m111_enable(struct mt9m111 *mt9m111)
> +static int mt9m111_set_output(struct mt9m111 *mt9m111, int on)
> {
> struct i2c_client *client = v4l2_get_subdevdata(&mt9m111->subdev);
> - return reg_write(RESET, MT9M111_RESET_CHIP_ENABLE);
> + int ret;
> +
> + if (on) {
> + ret = reg_clear(RESET, MT9M111_RESET_OUTPUT_DISABLE);
> + if (ret)
> + return ret;
> +
> + return reg_set(RESET, MT9M111_RESET_CHIP_ENABLE);
> + }
> +
> + /* disable */
> + ret = reg_set(RESET, MT9M111_RESET_OUTPUT_DISABLE);
> + if (ret)
> + return ret;
> +
> + return reg_clear(RESET, MT9M111_RESET_CHIP_ENABLE);

Unless the hardware specifically requires this sequence, I'd use the
inverse of the enable sequence here.

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

> }
>
> static int mt9m111_reset(struct mt9m111 *mt9m111)
> @@ -927,10 +942,7 @@ static int mt9m111_suspend(struct mt9m111 *mt9m111)
> ret = reg_set(RESET, MT9M111_RESET_RESET_MODE);
> if (!ret)
> ret = reg_set(RESET, MT9M111_RESET_RESET_SOC |
> - MT9M111_RESET_OUTPUT_DISABLE |
> MT9M111_RESET_ANALOG_STANDBY);
> - if (!ret)
> - ret = reg_clear(RESET, MT9M111_RESET_CHIP_ENABLE);
>
> return ret;
> }
> @@ -951,9 +963,9 @@ static void mt9m111_restore_state(struct mt9m111 *mt9m111)
>
> static int mt9m111_resume(struct mt9m111 *mt9m111)
> {
> - int ret = mt9m111_enable(mt9m111);
> - if (!ret)
> - ret = mt9m111_reset(mt9m111);
> + int ret;
> +
> + ret = mt9m111_reset(mt9m111);
> if (!ret)
> mt9m111_restore_state(mt9m111);
>
> @@ -965,9 +977,7 @@ static int mt9m111_init(struct mt9m111 *mt9m111)
> struct i2c_client *client = v4l2_get_subdevdata(&mt9m111->subdev);
> int ret;
>
> - ret = mt9m111_enable(mt9m111);
> - if (!ret)
> - ret = mt9m111_reset(mt9m111);
> + ret = mt9m111_reset(mt9m111);
> if (!ret)
> ret = mt9m111_set_context(mt9m111, mt9m111->ctx);
> if (ret)
> @@ -1116,8 +1126,14 @@ static int mt9m111_enum_mbus_code(struct v4l2_subdev *sd,
> static int mt9m111_s_stream(struct v4l2_subdev *sd, int enable)
> {
> struct mt9m111 *mt9m111 = container_of(sd, struct mt9m111, subdev);
> + int ret;
> +
> + ret = mt9m111_set_output(mt9m111, enable);
> + if (ret)
> + return ret;
>
> mt9m111->is_streaming = !!enable;
> +
> return 0;
> }
>

--
Regards,

Laurent Pinchart