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Randy Dunlap reports on the sparse list that sparse warns about this
expression:
of_irq->percpu ? free_percpu_irq(of_irq->irq, clkevt) :
free_irq(of_irq->irq, clkevt);
and honestly, sparse is correct to warn. The return type of
free_percpu_irq() is 'void', while free_irq() returns a 'const void *'
that is the devname argument passed in to the request_irq().
You can't mix a void type with a non-void types in a conditional
expression according to the C standard. It so happens that gcc seems to
accept it - and the resulting type of the expression is void - but
there's really no reason for the kernel to have this kind of
non-standard expression with no real upside.
The natural way to write that expression is with an if-statement:
if (of_irq->percpu)
free_percpu_irq(of_irq->irq, clkevt);
else
free_irq(of_irq->irq, clkevt);
which is more legible anyway.
I'm not sure why that timer-of code seems to have this odd pattern. It
does the same at allocation time, but at least there the types match,
and it makes sense as an expression.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linux kernel
============
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