Hi,
On 03/18/2015 10:31 PM, Wolfram Sang wrote:
> Hi,
>
> so, the bus recovery patches look fine to me in general.
>
> It is only this one question left which I always had with bus recovery.
> Maybe you guys can join me thinking about it.
Ok. Thanks and sorry for delayed reply - missed your e-mail :(
I'll resend them next week.
>
>> @@ -376,8 +366,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct
>> i2c_msg *msg, int stop)
>> dev->adapter.timeout);
>> if (r == 0) {
>> dev_err(dev->dev, "controller timed out\n");
>> - davinci_i2c_recover_bus(dev);
>> - i2c_davinci_init(dev);
>> + i2c_recover_bus(adap);
>> dev->buf_len = 0;
>> return -ETIMEDOUT;
>
> The I2C specs say in 3.1.16 that the recovery procedure should be used
> when SDA is stuck low. So, I do wonder if we should apply the recovery
> after a timeout. Stuck SDA might be one reason for timeout, but there
> may be others...
This is ancient code. And regarding your question -
Might be it would be reasonable to add call of
i2c_davinci_wait_bus_not_busy() at the end of i2c_davinci_xfer()?
This way we will wait for Bus Free before performing recovery.
Of course, i2c_davinci_wait_bus_not_busy() has to be fixed first
as proposed by Alexander Sverdlin here:
https://patchwork.ozlabs.org/patch/448994/.
--
regards,
-grygorii
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