Subject: Re: [PATCH] powerpc/powernv: fix a W=1 compilation warning

From: Qian Cai <[email-masked]>
Date: Tue, 03 Sep 2019 09:29:14 -0400

I saw Christ start to remove npu-dma.c code [1]

[1] https://lore.kernel.org/linuxppc-dev/[email-masked]/

Should pnv_npu_dma_set_32() be removed too?

It was only called by pnv_npu_try_dma_set_bypass() but the later is not used
anywhere in the kernel tree. If that is a case, I don't need to bother fixing
the warning here.

On Wed, 2019-05-22 at 12:09 -0400, Qian Cai wrote:
> The commit b575c731fe58 ("powerpc/powernv/npu: Add set/unset window
> helpers") called pnv_npu_set_window() in a void function
> pnv_npu_dma_set_32(), but the return code from pnv_npu_set_window() has
> no use there as all the error logging happen in pnv_npu_set_window(),
> so just remove the unused variable to avoid a compilation warning,
> 
> arch/powerpc/platforms/powernv/npu-dma.c: In function
> 'pnv_npu_dma_set_32':
> arch/powerpc/platforms/powernv/npu-dma.c:198:10: warning: variable ‘rc’
> set but not used [-Wunused-but-set-variable]
> 
> Signed-off-by: Qian Cai <[email-masked]>
> ---
>  arch/powerpc/platforms/powernv/npu-dma.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/npu-dma.c
> b/arch/powerpc/platforms/powernv/npu-dma.c
> index 495550432f3d..035208ed591f 100644
> --- a/arch/powerpc/platforms/powernv/npu-dma.c
> +++ b/arch/powerpc/platforms/powernv/npu-dma.c
> @@ -195,7 +195,6 @@ static void pnv_npu_dma_set_32(struct pnv_ioda_pe *npe)
>  {
>  	struct pci_dev *gpdev;
>  	struct pnv_ioda_pe *gpe;
> -	int64_t rc;
>  
>  	/*
>  	 * Find the assoicated PCI devices and get the dma window
> @@ -208,8 +207,8 @@ static void pnv_npu_dma_set_32(struct pnv_ioda_pe *npe)
>  	if (!gpe)
>  		return;
>  
> -	rc = pnv_npu_set_window(&npe->table_group, 0,
> -			gpe->table_group.tables[0]);
> +	pnv_npu_set_window(&npe->table_group, 0,
> +			   gpe->table_group.tables[0]);
>  
>  	/*
>  	 * NVLink devices use the same TCE table configuration as