Re: [PATCH v3 1/2] media: i2c: imx412: fix sensor power-on timing

From: Sakari Ailus

Date: Mon Jan 19 2026 - 06:35:00 EST


Hi Wenmeng,

On Mon, Jan 19, 2026 at 06:15:01PM +0800, Wenmeng Liu wrote:
> Assert the reset GPIO at the start of power-on, enable regulators and the
> clock, then deassert reset. This avoids a mismatch where the first
> power-up (when the reset GPIO defaults deasserted) differs from subsequent
> cycles.
>
> Signed-off-by: Wenmeng Liu <wenmeng.liu@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/i2c/imx412.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/i2c/imx412.c b/drivers/media/i2c/imx412.c
> index b3826f80354703b17b416dc233854da3f5736e38..ebc2fb706442365f541540bf4ce9d307d42e0061 100644
> --- a/drivers/media/i2c/imx412.c
> +++ b/drivers/media/i2c/imx412.c
> @@ -1022,6 +1022,8 @@ static int imx412_power_on(struct device *dev)
> struct imx412 *imx412 = to_imx412(sd);
> int ret;
>
> + gpiod_set_value_cansleep(imx412->reset_gpio, 1);

I'd assert reset in probe() so you can drop this line.

> +
> ret = regulator_bulk_enable(ARRAY_SIZE(imx412_supply_names),
> imx412->supplies);
> if (ret < 0) {
> @@ -1029,20 +1031,19 @@ static int imx412_power_on(struct device *dev)
> return ret;
> }
>
> - gpiod_set_value_cansleep(imx412->reset_gpio, 0);
> -
> ret = clk_prepare_enable(imx412->inclk);
> if (ret) {
> dev_err(imx412->dev, "fail to enable inclk\n");
> goto error_reset;
> }
>
> + gpiod_set_value_cansleep(imx412->reset_gpio, 0);
> +
> usleep_range(1000, 1200);
>
> return 0;
>
> error_reset:
> - gpiod_set_value_cansleep(imx412->reset_gpio, 1);
> regulator_bulk_disable(ARRAY_SIZE(imx412_supply_names),
> imx412->supplies);
>
>

--
Regards,

Sakari Ailus