Re: [PATCH v2 2/9] dmapool: cleanup error messages

[Tony Battersby <tonyb@cybernetics.com>]

On 08/03/2018 04:56 AM, Andy Shevchenko wrote:
> On Thu, Aug 2, 2018 at 10:57 PM, Tony Battersby <tonyb@cybernetics.com> wrote:
>> Remove code duplication in error messages.  It is now safe to pas a NULL
>> dev to dev_err(), so the checks to avoid doing so are no longer
>> necessary.
>>
>> Example:
>>
>> Error message with dev != NULL:
>>   mpt3sas 0000:02:00.0: dma_pool_destroy chain pool, (____ptrval____) busy
>>
>> Same error message with dev == NULL before patch:
>>   dma_pool_destroy chain pool, (____ptrval____) busy
>>
>> Same error message with dev == NULL after patch:
>>   (NULL device *): dma_pool_destroy chain pool, (____ptrval____) busy
> Have you checked a history of this?
>
> I'm pretty sure this was created in an order to avoid bad looking (and
> in some cases frightening) "NULL device *" part.
>
> If it it's the case, I would rather leave it as is, and even not the
> case, I'm slightly more bent to the current state.
>
I did.A  "drivers/base/dmapool.c", later moved to "mm/dmapool.c", was
added in linux-2.6.3, for which dev_err() did not work will a NULL dev,
so the check was necessary back then.A  I agree that the (NULL device *):
bit is ugly, but these messages should be printed only after a kernel
bug, so it is not like they will be making a regular appearance in
dmesg.A  Considering that, I think that it is better to keep it simple.