Re: [PATCH 2/3] i2c: davinci: Refactor i2c_davinci_wait_bus_not_busy()

[Alexander Sverdlin <alexander.sverdlin-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>]

Hi!

On 12/03/15 13:37, ext Grygorii Strashko wrote:
>>>> +    if (i2c_davinci_wait_status_change(dev, DAVINCI_I2C_STR_BB, 0)) {
>>>> >>> +        dev_warn(dev->dev, "timeout waiting for bus ready\n");
>>>> >>> +        davinci_i2c_recover_bus(dev);
>>>> >>> +        i2c_davinci_init(dev);
>>>> >>> +        /*
>>>> >>> +         * the bus should not be busy after init, otherwise something
>>>> >>> +         * is badly broken
>>>> >>> +         */
>>> >>
>>> >> I think you should recheck BB and return error if it's still detected.
>> >
>> > But after re-reading the datasheet, I must conclude, this is almost not possible.
>> > It will be a dead code. Reset will clear BB anyway and the only possibility to see
>> > BB set to 1 here is when another master transmits right after our reset. We cannot
>> > guarantee that we will always catch this here, so this must be any way handled over
>> > AL interrupt.
> The question here what is worse:
> - silently continue execution with undefined behavior
> - or recheck and return error (That's how it was before).
> 
> I like option 2 :) - don't believe HW.

OK, it will at least catch the cases when the bus is short-circuited.

-- 
Best regards,
Alexander Sverdlin.