Re: [PATCH v5 01/36] i2c: tegra: Make tegra_i2c_flush_fifos() usable in atomic transfer

[Dmitry Osipenko]

07.09.2020 10:56, Andy Shevchenko пишет:
> On Sun, Sep 6, 2020 at 9:51 PM Dmitry Osipenko <digetx@xxxxxxxxx> wrote:
>>
>> The tegra_i2c_flush_fifos() shouldn't sleep in atomic transfer and jiffies
>> are not updating if interrupts are disabled. Let's switch to use iopoll
>> API helpers for register-polling. The iopoll API provides helpers for both
>> atomic and non-atomic cases.
>>
>> Note that this patch doesn't fix any known problem because normally FIFO
>> is flushed at the time of starting a new transfer.
> 
> ...
> 
>> +       if (i2c_dev->is_curr_atomic_xfer)
>> +               err = readl_relaxed_poll_timeout_atomic(addr, val, !(val & mask),
>> +                                                       1000, 1000000);
>> +       else
>> +               err = readl_relaxed_poll_timeout(addr, val, !(val & mask),
>> +                                                1000, 1000000);
>> +
>> +       if (err) {
>> +               dev_err(i2c_dev->dev, "failed to flush FIFO\n");
> 
>> +               return err;
>>         }
>>         return 0;
> 
> return err; ?
> 

The return 0 is intentional here because returned "err" implies that
error happened and error code is returned, while 0 explicitly shows the
success status. Hence it's always cleaner and more expressive to
directly return 0 on success, IMO. I'd prefer to keep this part as-is.