On 08/03/2018 04:56 AM, Andy Shevchenko wrote: > On Thu, Aug 2, 2018 at 10:57 PM, Tony Battersby <tonyb@xxxxxxxxxxxxxxx> 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. "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. 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. Considering that, I think that it is better to keep it simple.
