Re: [PATCH 2/3] [media] mt9v032: Do not unset master_mode

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Markus,

Thank you for the patch.

On Friday 06 November 2015 14:13:44 Markus Pargmann wrote:
> The power_on function of the driver resets the chip and sets the
> CHIP_CONTROL register to 0. This switches the operating mode to slave.
> The s_stream function sets the correct mode. But this caused problems on
> a board where the camera chip is operated as master. The camera started
> after a random amount of time streaming an image, I observed between 10
> and 300 seconds.
> 
> The STRFM_OUT and STLN_OUT pins are not connected on this board which
> may cause some issues in slave mode. I could not find any documentation
> about this.
> 
> Keeping the chip in master mode after the reset helped to fix this
> issue for me.
> 
> Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
> ---
>  drivers/media/i2c/mt9v032.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/i2c/mt9v032.c b/drivers/media/i2c/mt9v032.c
> index 4aefde9634f5..943c3f39ea73 100644
> --- a/drivers/media/i2c/mt9v032.c
> +++ b/drivers/media/i2c/mt9v032.c
> @@ -344,7 +344,8 @@ static int mt9v032_power_on(struct mt9v032 *mt9v032)
>  	if (ret < 0)
>  		return ret;
> 
> -	return regmap_write(map, MT9V032_CHIP_CONTROL, 0);
> +	return regmap_write(map, MT9V032_CHIP_CONTROL,
> +			    MT9V032_CHIP_CONTROL_MASTER_MODE);

This makes sense, but shouldn't you also fix the mt9v032_s_stream() function 
then ? It clears the MT9V032_CHIP_CONTROL_MASTER_MODE bit when turning the 
stream off.

>  }
> 
>  static void mt9v032_power_off(struct mt9v032 *mt9v032)

-- 
Regards,

Laurent Pinchart