From: Bjorn Helgaas <helgaas@kernel.org>
To: "Krzysztof Wilczyński" <kw@linux.com>
Cc: Rob Herring <robh@kernel.org>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
linux-pci@vger.kernel.org, Duc Dang <dhdang@apm.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Toan Le <toan@os.amperecomputing.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] PCI: xgene: Remove unused assignment to variable msi_val
Date: Tue, 22 Sep 2020 09:52:45 -0500 [thread overview]
Message-ID: <20200922145245.GA2201556@bjorn-Precision-5520> (raw)
In-Reply-To: <20200922030257.459898-1-kw@linux.com>
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@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@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
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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next prev parent reply other threads:[~2020-09-22 14:54 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-22 3:02 [PATCH] PCI: xgene: Remove unused assignment to variable msi_val Krzysztof Wilczyński
2020-09-22 14:52 ` Bjorn Helgaas [this message]
2020-10-01 14:42 ` Rob Herring
2020-10-02 12:00 ` Lorenzo Pieralisi
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