Re: [PATCH v2 06/18] m68k: Replace setup_irq() by request_irq()

[Finn Thain]

On Wed, 26 Feb 2020, Greg Ungerer wrote:

> On 26/2/20 4:39 pm, Finn Thain wrote:
> > 
> > If -EBUSY means the end user has misconfigured something, printing
> > "request_irq failed" would be helpful. But does that still happen?
> 
> I have seen it many times. Its not at all difficult to get interrupt 
> assignments wrong, duplicated, or otherwise mistaken when creating 
> device trees. Not so much m68k/coldfire platforms where they are most 
> commonly hard coded.
> 

I was thinking of end users and production builds. You seem to be 
concerned about developers. Catering to developers argues for pr_debug() 
here, if anything.

You say you've seen -16 errors "many times". Have you also seen -22? Did 
the ability to distinguish these values help you to fix your device tree?

> > ...
> > 
> > BTW, one of the benefits of "%s: request_irq failed" is that a 
> > compilation unit with multiple request_irq calls permits the compiler 
> > to coalesce all duplicated format strings. Whereas, that's not 
> > possible with "foo: request_irq failed" and "bar: request_irq failed".
> 
> Given the wide variety of message text used with failed request_irq() 
> calls it would be shear luck that this matched anything else. A quick 
> grep shows that "%s: request_irq() failed\n" has no other exact matches 
> in the current kernel source.
> 

You are overlooking the patches in this series that produce multiple 
identical format strings.

And the present lack of consistency isn't a great argument for more 
inconsistency IMO.