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

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On 2018-07-16 12:37, Geert Uytterhoeven wrote:
> 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?

No!

Above this, there is this line:

#define RECOVERY_NDELAY		5000

Cheers,
Peter

>>         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
> 




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