Re: [PATCH] MIPS: Squash pci_fixup_irqs() compiler warning

[David Daney <ddaney.cavm@gmail.com>]

On 04/17/2011 12:01 PM, Kevin Cernekee wrote:
> MIPS Linux is unique in that it uses a "const struct pci_dev *" argument
> to discourage bad coding practices in pcibios_map_irq().  Add a cast so
> that this warning goes away:
>
> arch/mips/pci/pci.c: In function 'pcibios_init':
> arch/mips/pci/pci.c:165:45: warning: passing argument 2 of 'pci_fixup_irqs' 
> from incompatible pointer type
> include/linux/pci.h:856:6: note: expected 'int (*)(struct pci_dev *, u8,  u8)' 
> but argument is of type 'struct pci_dev *'
>
> Signed-off-by: Kevin Cernekee<cernekee@gmail.com>
> ---
>
> Reference:
>
> http://www.mail-archive.com/gnewsense-dev@nongnu.org/msg00706.html
>
> It's been two years since the original discussion, and the warning is
> still there.  It is now the only warning left in my kernel build.
>
> I was hoping we could get this resolved for good (one way or another).
>
>   arch/mips/pci/pci.c |    3 ++-
>   1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/arch/mips/pci/pci.c b/arch/mips/pci/pci.c
> index 33bba7b..9a35cd6 100644
> --- a/arch/mips/pci/pci.c
> +++ b/arch/mips/pci/pci.c
> @@ -157,7 +157,8 @@ static int __init pcibios_init(void)
>         for (hose = hose_head; hose; hose = hose->next)
>                 pcibios_scanbus(hose);
>
> -       pci_fixup_irqs(pci_common_swizzle, pcibios_map_irq);
> +       pci_fixup_irqs(pci_common_swizzle,
> +                      (int (*)(struct pci_dev *, u8, u8))pcibios_map_irq);
NAK.

I think Ralf's idea in the e-mail you referenced is the proper approach.

Change pci_fixup_irqs(...) to take a 'const struct pci_dev *' instead. 
There is a lot of work going on in the kernel to constify things.  This 
should be fairly easy to get accepted.
The alternative is to change all the pcibios_map_irq to match what is 
expected by pci_fixup_irqs().
David Daney


>         pci_initialized = 1;