Re: [PATCH] x86/pmc_atom: Fix warning when CONFIG_DEBUG_FS=n

[Ingo Molnar <mingo@kernel.org>]

* Martin Kelly <martin@martingkelly.com> wrote:

> When compiling with CONFIG_DEBUG_FS=n, gcc emits an unused variable
> warning for pmc_atom.c because "ret" is used only within the
> CONFIG_DEBUG_FS block. This patch fixes it up to eliminate "ret" when
> CONFIG_DEBUG_FS=n.
> 
> Signed-off-by: Martin Kelly <martkell@amazon.com>
> ---
>  arch/x86/kernel/pmc_atom.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/x86/kernel/pmc_atom.c b/arch/x86/kernel/pmc_atom.c
> index 0c424a6..66e7d88 100644
> --- a/arch/x86/kernel/pmc_atom.c
> +++ b/arch/x86/kernel/pmc_atom.c
> @@ -240,7 +240,9 @@ err:
>  static int pmc_setup_dev(struct pci_dev *pdev)
>  {
>  	struct pmc_dev *pmc = &pmc_device;
> +#ifdef CONFIG_DEBUG_FS
>  	int ret;
> +#endif /* CONFIG_DEBUG_FS */
>  
>  	/* Obtain ACPI base address */
>  	pci_read_config_dword(pdev, ACPI_BASE_ADDR_OFFSET, &acpi_base_addr);

This uglifies the code which is bad. A nicer fix would be to 
improve the code: for example define pmc_dbgfs_register() in the 
!DEBUG_FS case as well, with a return 0 or so.

Thanks,

	Ingo