Hi Andy,
Thanks for the review.
On 10/25/22 12:18, Andy Shevchenko wrote:
> On Tue, Oct 25, 2022 at 11:50:59AM +0300, Matti Vaittinen wrote:
>> The fwnode_irq_get_byname() does return 0 upon device-tree IRQ mapping
>> failure. This is contradicting the function documentation and can
>> potentially be a source of errors like:
>>
>> int probe(...) {
>> ...
>>
>> irq = fwnode_irq_get_byname();
>> if (irq <= 0)
>> return irq;
>>
>> ...
>> }
>>
>> Here we do correctly check the return value from fwnode_irq_get_byname()
>> but the driver probe will now return success. (There was already one
>> such user in-tree).
>>
>> Change the fwnode_irq_get_byname() to work as documented and according to
>> the common convention and abd always return a negative errno upon failure.
>
> ...
>
>> + ret = fwnode_irq_get(fwnode, index);
>
>> +
>
> Redundant blank line and better to use traditional pattern: >
>> + if (!ret)
>> + return -EINVAL;
>> +
>> + return ret;
>
> if (ret)
> return ret;
>
> /* We treat mapping errors as invalid case */
> return -EINVAL;
>
>> }
I like the added comment - but in this case I don't prefer the
"traditional pattern" you suggest. We do check for a very special error
case indicated by ret 0.
if (!ret)
return -EINVAL;
makes it obvious the zero is special error.
if (ret)
return ret;
the traditional pattern makes this look like traditional error return -
which it is not. The comment you added is nice though. It could be just
before the check for
if (!ret).
I can cook v2 later when I have finished my current task - which may or
may not take a while though....
Yours
-- Matti
--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland
~~ When things go utterly wrong vim users can always type :help! ~~
