Re: [PATCH] i2c: recovery: make pin init look like STOP

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On Thu, Jul 12, 2018 at 7:49 PM Wolfram Sang
<wsa+renesas@xxxxxxxxxxxxxxxxxxxx> wrote:
> When we we initialize the pins, make sure it looks like STOP by dividing
> the delay into halves. It shouldn't matter because SDA is expected to be
> held low by a device, but for super-safety, let's do it.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/i2c/i2c-core-base.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index 51cbb0c158f2..e57231ccb32a 100644
> --- a/drivers/i2c/i2c-core-base.c
> +++ b/drivers/i2c/i2c-core-base.c
> @@ -191,9 +191,10 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap)
>                 bri->prepare_recovery(adap);
>
>         bri->set_scl(adap, scl);
> +       ndelay(RECOVERY_NDELAY / 2);

Any change someone changes RECOVERY_NDELAY to 1, leading to a
zero delay here? Is that an issue?

>         if (bri->set_sda)
> -               bri->set_sda(adap, 1);
> -       ndelay(RECOVERY_NDELAY);
> +               bri->set_sda(adap, scl);
> +       ndelay(RECOVERY_NDELAY / 2);
>
>         /*
>          * By this time SCL is high, as we need to give 9 falling-rising edges

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



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