Re: i2c-HID: Delete unnecessary checks before the function call "gpiod_put"
From: SF Markus Elfring
Date: Thu Jul 09 2015 - 16:49:39 EST
>>> The gpiod_put() function performs also input parameter validation
>>> by forwarding its single input pointer to the gpiod_free() function.
>>> Thus the test around the calls is not needed.
>>>
>>> This issue was detected by using the Coccinelle software.
>>>
>>> Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
>>
>> As Dan correctly pointed out, this is not as straightforward as it might
>> seem on a firsr sight, because there is a WARN_ON() that might start
>> triggering in case of !ihid->desc.
>>
>> Adding Benjamin. I am not applying this without his Ack.
>>
>
> I think the gpiod case is the exception rather than the common rule
> (most i2c-hid device we saw until recently were using irqs, not
> gpios). So if I understand correctly, removing the check on ihid->desc
> would raise a warning for most devices. This is IMO not a good thing,
> so I would say NACK.
>
> Mika might have a different opinion though.
The proposed update candidates are contained in the source
file "drivers/hid/i2c-hid/i2c-hid.c" from Linux next-20150708.
* i2c_hid_remove() function:
Can it be tolerated here that the pointer "ihid->desc" might be eventually null?
* i2c_hid_probe() function:
Is this implementation structured in such a way that a pointer for valid data
will be usually passed for "ihid->desc" if the statements after the jump
label "err" will be reached?
Regards,
Markus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/