On 15/03/2021 13:15, Jacopo Mondi wrote:
> It has been observed through repeated testing (250 boots) that in the
> 10% of the cases the RDACM21 initialization sequence errors out due a
> timeout waiting for the OV490 firmware to complete its boot phase.
>
> Albeit being the current timeout relatively large (300-600 milliseconds),
> doubling it reduces the sporadic error rate down to 1 over an 80 boot
> sequences test run.
>
> The firmware boot delay is unfortunately not characterized in the camera
> module manual.
>
I wonder if we could characterize this alone by pulling this down until
we see failures increase, with all the other fixes in place...
I don't think that's required, but it might be something to check later
if we don't get rid of that 1/80 failure.
> Fixes: a59f853b3b4b ("media: i2c: Add driver for RDACM21 camera module")
> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/i2c/rdacm21.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c
> index 50a9b0d8255d..07cf077d8efd 100644
> --- a/drivers/media/i2c/rdacm21.c
> +++ b/drivers/media/i2c/rdacm21.c
> @@ -53,7 +53,7 @@
> #define OV490_PID 0x8080300a
> #define OV490_VER 0x8080300b
> #define OV490_PID_TIMEOUT 20
> -#define OV490_OUTPUT_EN_TIMEOUT 300
> +#define OV490_OUTPUT_EN_TIMEOUT 600
>
> #define OV490_GPIO0 BIT(0)
> #define OV490_SPWDN0 BIT(0)
>
