Re: [PATCH v1 3/5] drivers: media: bcm2835-unicam: Disable trigger mode operation

Jacopo Mondi
2024-11-22T11:18:16Z

Hi Naush

On Fri, Nov 22, 2024 at 08:41:50AM +0000, Naushir Patuck wrote:
> The imx219/imx708 sensors frequently generate a single corrupt frame
> (image or embedded data) when the sensor first starts. This can either
> be a missing line, or invalid samples within the line. This only occurrs
> using the upstream Unicam kernel driver.

I think the last statement can b dropped.

>
> Disabling trigger mode elimiates this corruption. Since trigger mode is
> a legacy feature copied from the firmware driver and not expected to be
> needed, remove it. Tested on the Raspberry Pi cameras and shows no ill
> effects.
>
> Signed-off-by: Naushir Patuck <naush@raspberrypi.com>

Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>

Thanks
j

> ---
> drivers/media/platform/broadcom/bcm2835-unicam.c | 8 +-------
> 1 file changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/drivers/media/platform/broadcom/bcm2835-unicam.c b/drivers/media/platform/broadcom/bcm2835-unicam.c
> index d573d4d89881..550eb1b064f1 100644
> --- a/drivers/media/platform/broadcom/bcm2835-unicam.c
> +++ b/drivers/media/platform/broadcom/bcm2835-unicam.c
> @@ -834,11 +834,6 @@ static irqreturn_t unicam_isr(int irq, void *dev)
> }
> }
>
> - if (unicam_reg_read(unicam, UNICAM_ICTL) & UNICAM_FCM) {
> - /* Switch out of trigger mode if selected */
> - unicam_reg_write_field(unicam, UNICAM_ICTL, 1, UNICAM_TFC);
> - unicam_reg_write_field(unicam, UNICAM_ICTL, 0, UNICAM_FCM);
> - }
> return IRQ_HANDLED;
> }
>
> @@ -1002,8 +997,7 @@ static void unicam_start_rx(struct unicam_device *unicam,
>
> unicam_reg_write_field(unicam, UNICAM_ANA, 0, UNICAM_DDL);
>
> - /* Always start in trigger frame capture mode (UNICAM_FCM set) */
> - val = UNICAM_FSIE | UNICAM_FEIE | UNICAM_FCM | UNICAM_IBOB;
> + val = UNICAM_FSIE | UNICAM_FEIE | UNICAM_IBOB;
> line_int_freq = max(fmt->height >> 2, 128);
> unicam_set_field(&val, line_int_freq, UNICAM_LCIE_MASK);
> unicam_reg_write(unicam, UNICAM_ICTL, val);
> --
> 2.34.1
>
>