On 2018-05-10 10:36, Andrzej Hajda wrote:
> On 09.05.2018 21:45, Peter Rosin wrote:
>> The else branch cannot be taken as i will always equal num.
>> Get rid of the whole construct.
>>
>> Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
>> ---
>> drivers/i2c/busses/i2c-exynos5.c | 12 +-----------
>> 1 file changed, 1 insertion(+), 11 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
>> index 12ec8484e653..a2cbc779c33a 100644
>> --- a/drivers/i2c/busses/i2c-exynos5.c
>> +++ b/drivers/i2c/busses/i2c-exynos5.c
>> @@ -727,17 +727,7 @@ static int exynos5_i2c_xfer(struct i2c_adapter *adap,
>> goto out;
>> }
>>
>> - if (i == num) {
>> - ret = num;
>> - } else {
>> - /* Only one message, cannot access the device */
>> - if (i == 1)
>> - ret = -EREMOTEIO;
>> - else
>> - ret = i;
>> -
>> - dev_warn(i2c->dev, "xfer message failed\n");
>> - }
>> + ret = num;
>>
>> out:
>> clk_disable(i2c->clk);
>
> You can go further and remove "out:" label, use break instead, and at
> the end use "return (i == num) ? num : ret;" or sth similar.
>
> With this change you can add:
>
> Reviewed-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
But then the patch wouldn't be so obviously safe. If I would write
a function equivalent to the original function, I think I'd write
something like:
static int exynos5_i2c_xfer(struct i2c_adapter *adap,
struct i2c_msg *msgs, int num)
{
struct exynos5_i2c *i2c = adap->algo_data;
int i, ret;
if (i2c->suspended) {
dev_err(i2c->dev, "HS-I2C is not initialized.\n");
return -EIO;
}
ret = clk_enable(i2c->clk);
if (ret)
return ret;
for (i = 0; !ret && i < num; i++)
ret = exynos5_i2c_xfer_msg(i2c, msgs + i, i == num - 1);
clk_disable(i2c->clk);
return ret ?: num;
}
And I think that is safe because I don't see any possibility for
exynos_i2c_xfer_msg to return anything but zero success or negative
errors. Since I can only compile-test, so I do not feel all that
good about going further than I did.
But if you or anyone can test the above function, feel free to make
a patch out of it. I don't care enough to make a bunch of iterations
on these trivialities. I just spotted dead code and dumb initializers
while looking for other things. So, take it or leave it. I.e. it was
just a couple of drive-by patches.
Cheers,
Peter
