[PATCH] PCI: xgene: Remove unused assignment to variable msi_val

Bjorn Helgaas helgaas at kernel.org
Tue Sep 22 10:52:45 EDT 2020


On Tue, Sep 22, 2020 at 03:02:57AM +0000, Krzysztof Wilczyński wrote:
> The value assigned to msi_val after the inner loop finishes its run is
> never used for anything, and it is also immediately overridden in the
> line that follows with the return value from the xgene_msi_int_read()
> function.
> 
> Since the value of msi_val following the inner loop completion is never
> used in any meaningful way the assignment can be removed.
> 
> Addresses-Coverity-ID: 1437183 ("Unused value")
> Signed-off-by: Krzysztof Wilczyński <kw at linux.com>
> ---
>  drivers/pci/controller/pci-xgene-msi.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/controller/pci-xgene-msi.c b/drivers/pci/controller/pci-xgene-msi.c
> index 02271c6d17a1..2470782cb01a 100644
> --- a/drivers/pci/controller/pci-xgene-msi.c
> +++ b/drivers/pci/controller/pci-xgene-msi.c
> @@ -493,8 +493,8 @@ static int xgene_msi_probe(struct platform_device *pdev)
>  	 */
>  	for (irq_index = 0; irq_index < NR_HW_IRQS; irq_index++) {
>  		for (msi_idx = 0; msi_idx < IDX_PER_GROUP; msi_idx++)
> -			msi_val = xgene_msi_ir_read(xgene_msi, irq_index,
> -						    msi_idx);
> +			xgene_msi_ir_read(xgene_msi, irq_index, msi_idx);
> +

Interesting.  One might expect that throwing away the result of a read
means the read itself is pointless, but fortunately there's a comment
just above explaining that these registers are read-to-clear.

Acked-by: Bjorn Helgaas <bhelgaas at google.com>

Assuming Toan acks this, Lorenzo will likely pick it up when he
returns next week.

>  		/* Read MSIINTn to confirm */
>  		msi_val = xgene_msi_int_read(xgene_msi, irq_index);
>  		if (msi_val) {
> -- 
> 2.28.0
> 
> 
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