Hi Jacopo,
On Thu, Nov 4, 2021 at 12:10 PM Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> wrote:
> Valid pixel clock detection is performed by spinning on a register read
> which if repeated too frequently might fail. As the error is not fatal
> ignore it instead of bailing out to continue spinning until the timeout
> completion.
>
> Also relax the time between bus transactions and slightly increase the
> wait interval to mitigate the failure risk.
>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> ---
>
> v1->v2:
> - Do not continue but jump to a label to respect the sleep timout after a
> failed read
Thanks for the update!
> --- a/drivers/media/i2c/max9271.c
> +++ b/drivers/media/i2c/max9271.c
> @@ -55,7 +55,7 @@ static int max9271_write(struct max9271_device *dev, u8 reg, u8 val)
> /*
> * max9271_pclk_detect() - Detect valid pixel clock from image sensor
> *
> - * Wait up to 10ms for a valid pixel clock.
> + * Wait up to 15ms for a valid pixel clock.
> *
> * Returns 0 for success, < 0 for pixel clock not properly detected
> */
> @@ -64,15 +64,16 @@ static int max9271_pclk_detect(struct max9271_device *dev)
> unsigned int i;
> int ret;
>
> - for (i = 0; i < 100; i++) {
> + for (i = 0; i < 10; i++) {
> ret = max9271_read(dev, 0x15);
> if (ret < 0)
> - return ret;
> + goto skip;
Edgar Dijkstra: Go To Statement Considered Harmful?
>
> if (ret & MAX9271_PCLKDET)
"if (ret > 0 && (ret & MAX9271_PCLKDET))"?
> return 0;
>
> - usleep_range(50, 100);
> +skip:
> + usleep_range(1000, 1500);
> }
>
> dev_err(&dev->client->dev, "Unable to detect valid pixel clock\n");
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
