Hi Benjamin,
On Wed, Aug 28, 2024 at 08:13:07PM +0200, Benjamin Bara wrote:
> Currently, the V4L2 subdevice is also created when the device is not
> available/connected. In this case, dmesg shows the following:
>
> [ 10.419510] imx290 7-001a: Error writing reg 0x301c: -6
> [ 10.428981] imx290 7-001a: Error writing reg 0x3020: -6
> [ 10.442712] imx290 7-001a: Error writing reg 0x3018: -6
> [ 10.454018] imx290 7-001a: Error writing reg 0x3020: -6
>
> which seems to come from imx290_ctrl_update() after the subdev init is
> finished. However, as the errors are ignored, the subdev is initialized
> but simply does not work. From userspace perspective, there is no
> visible difference between a working and not-working subdevice (except
> when trying it out or watching for the error message).
>
> This commit adds a simple availability check before starting with the
> subdev initialization to error out instead.
>
> Signed-off-by: Benjamin Bara <benjamin.bara@xxxxxxxxxxx>
> ---
> Changes since v1:
> - define operating/standby mode and use it
> - read out the standby mode during probe and ensure it is standby
> ---
> drivers/media/i2c/imx290.c | 17 +++++++++++++++--
> 1 file changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/i2c/imx290.c b/drivers/media/i2c/imx290.c
> index 4150e6e4b9a6..2a869576600c 100644
> --- a/drivers/media/i2c/imx290.c
> +++ b/drivers/media/i2c/imx290.c
> @@ -29,6 +29,8 @@
> #include <media/v4l2-subdev.h>
>
> #define IMX290_STANDBY CCI_REG8(0x3000)
> +#define IMX290_STANDBY_OPERATING (0 << 0)
> +#define IMX290_STANDBY_STANDBY (1 << 0)
> #define IMX290_REGHOLD CCI_REG8(0x3001)
> #define IMX290_XMSTA CCI_REG8(0x3002)
> #define IMX290_ADBIT CCI_REG8(0x3005)
> @@ -1016,7 +1018,7 @@ static int imx290_start_streaming(struct imx290 *imx290,
> return ret;
> }
>
> - cci_write(imx290->regmap, IMX290_STANDBY, 0x00, &ret);
> + cci_write(imx290->regmap, IMX290_STANDBY, IMX290_STANDBY_OPERATING, &ret);
Please run
./scripts/checkpatch.pl --strict --max-line-length=80
the next time. I'll wrap the line this time.
>
> msleep(30);
>
> @@ -1029,7 +1031,7 @@ static int imx290_stop_streaming(struct imx290 *imx290)
> {
> int ret = 0;
>
> - cci_write(imx290->regmap, IMX290_STANDBY, 0x01, &ret);
> + cci_write(imx290->regmap, IMX290_STANDBY, IMX290_STANDBY_STANDBY, &ret);
>
> msleep(30);
>
> @@ -1520,6 +1522,7 @@ static int imx290_probe(struct i2c_client *client)
> {
> struct device *dev = &client->dev;
> struct imx290 *imx290;
> + u64 val;
> int ret;
>
> imx290 = devm_kzalloc(dev, sizeof(*imx290), GFP_KERNEL);
> @@ -1580,6 +1583,16 @@ static int imx290_probe(struct i2c_client *client)
> pm_runtime_set_autosuspend_delay(dev, 1000);
> pm_runtime_use_autosuspend(dev);
>
> + /* Make sure the sensor is available before V4L2 subdev init. */
> + ret = cci_read(imx290->regmap, IMX290_STANDBY, &val, NULL);
> + if (ret)
> + goto err_pm;
> + if (val != IMX290_STANDBY_STANDBY) {
> + dev_err(dev, "Sensor is not in standby mode\n");
> + ret = -ENODEV;
> + goto err_pm;
> + }
> +
> /* Initialize the V4L2 subdev. */
> ret = imx290_subdev_init(imx290);
> if (ret)
>
--
Kind regards,
Sakari Ailus
