From: Bjorn Helgaas <helgaas@kernel.org>
To: "Krzysztof Wilczyński" <kw@linux.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
Logan Gunthorpe <logang@deltatee.com>,
Joe Perches <joe@perches.com>,
Oliver O'Halloran <oohall@gmail.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Tyrel Datwyler <tyreld@linux.ibm.com>,
Russell Currey <ruscur@russell.cc>,
Kurt Schwemmer <kurt.schwemmer@microsemi.com>,
Vidya Sagar <vidyas@nvidia.com>,
Xiongfeng Wang <wangxiongfeng2@huawei.com>,
linux-pci@vger.kernel.org,
Alex Williamson <alex.williamson@redhat.com>
Subject: Re: [PATCH v6 5/6] PCI/sysfs: Only show value when driver_override is not NULL
Date: Thu, 3 Jun 2021 18:23:34 -0500 [thread overview]
Message-ID: <20210603232334.GA2153375@bjorn-Precision-5520> (raw)
In-Reply-To: <20210603000112.703037-6-kw@linux.com>
[+cc Alex, FYI]
On Thu, Jun 03, 2021 at 12:01:11AM +0000, Krzysztof Wilczyński wrote:
> Only expose the value of the "driver_override" variable through the
> corresponding sysfs object when a value is actually set.
This changes the attribute contents from "(null)" to an empty
(zero-length) file when no driver override has been set.
There are a few other driver_override_show() functions. Most don't
check the pointer so they'll show "(null)". One (spi.c) checks and
shows an empty string ("", file containing a single NULL character)
instead of an empty (zero-length) file.
> Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
> Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
> ---
> drivers/pci/pci-sysfs.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> index 5d63df7c1820..4e9f582ca10f 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -580,10 +580,11 @@ static ssize_t driver_override_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> struct pci_dev *pdev = to_pci_dev(dev);
> - ssize_t len;
> + ssize_t len = 0;
>
> device_lock(dev);
> - len = sysfs_emit(buf, "%s\n", pdev->driver_override);
> + if (pdev->driver_override)
> + len = sysfs_emit(buf, "%s\n", pdev->driver_override);
> device_unlock(dev);
> return len;
> }
> --
> 2.31.1
>
next prev parent reply other threads:[~2021-06-03 23:23 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-03 0:01 [PATCH v6 0/6] PCI/sysfs: Use sysfs_emit() and sysfs_emit_at() in "show" functions Krzysztof Wilczyński
2021-06-03 0:01 ` [PATCH v6 1/6] " Krzysztof Wilczyński
2021-06-03 0:01 ` [PATCH v6 2/6] PCI/sysfs: Use return value from dsm_label_utf16s_to_utf8s() directly Krzysztof Wilczyński
2021-06-03 0:01 ` [PATCH v6 3/6] PCI/sysfs: Fix trailing newline handling of resource_alignment_param Krzysztof Wilczyński
2021-06-03 23:40 ` Bjorn Helgaas
2021-06-04 13:25 ` Krzysztof Wilczyński
2021-06-03 0:01 ` [PATCH v6 4/6] PCI/sysfs: Add missing trailing newline to devspec_show() Krzysztof Wilczyński
2021-06-03 23:00 ` Bjorn Helgaas
2021-06-03 0:01 ` [PATCH v6 5/6] PCI/sysfs: Only show value when driver_override is not NULL Krzysztof Wilczyński
2021-06-03 21:17 ` Bjorn Helgaas
2021-06-03 21:37 ` Bjorn Helgaas
2021-06-03 22:19 ` Krzysztof Wilczyński
2021-06-03 23:23 ` Bjorn Helgaas [this message]
2021-06-04 0:47 ` Alex Williamson
2021-06-04 1:10 ` Krzysztof Wilczyński
2021-06-03 0:01 ` [PATCH v6 6/6] PCI/sysfs: Fix a buffer overrun problem with dsm_label_utf16s_to_utf8s() Krzysztof Wilczyński
2021-06-04 4:07 ` [PATCH v6 0/6] PCI/sysfs: Use sysfs_emit() and sysfs_emit_at() in "show" functions Bjorn Helgaas
2021-06-04 13:38 ` Krzysztof Wilczyński
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