diff mbox series

[v2,04/14] PCI/MSI: Use sysfs_emit() and sysfs_emit_at() in "show" functions

Message ID 20210515052434.1413236-4-kw@linux.com
State Not Applicable
Headers show
Series [v2,01/14] PCI: Use sysfs_emit() and sysfs_emit_at() in "show" functions | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch powerpc/merge (b68d19e1abdbafef9481c7c0b0bcaff34d7af17d)
snowpatch_ozlabs/checkpatch warning total: 1 errors, 1 warnings, 0 checks, 10 lines checked
snowpatch_ozlabs/needsstable success Patch has no Fixes tags

Commit Message

Krzysztof Wilczyński May 15, 2021, 5:24 a.m. UTC
The sysfs_emit() and sysfs_emit_at() functions were introduced to make
it less ambiguous which function is preferred when writing to the output
buffer in a device attribute's "show" callback [1].

Convert the PCI sysfs object "show" functions from sprintf(), snprintf()
and scnprintf() to sysfs_emit() and sysfs_emit_at() accordingly, as the
latter is aware of the PAGE_SIZE buffer and correctly returns the number
of bytes written into the buffer.

No functional change intended.

[1] Documentation/filesystems/sysfs.rst

Related to:
  commit ad025f8e46f3 ("PCI/sysfs: Use sysfs_emit() and sysfs_emit_at() in "show" functions")

Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
---
 drivers/pci/msi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Joe Perches May 15, 2021, 5:46 a.m. UTC | #1
On Sat, 2021-05-15 at 05:24 +0000, Krzysztof Wilczyński wrote:
> The sysfs_emit() and sysfs_emit_at() functions were introduced to make
> it less ambiguous which function is preferred when writing to the output
> buffer in a device attribute's "show" callback [1].
> 
> Convert the PCI sysfs object "show" functions from sprintf(), snprintf()
> and scnprintf() to sysfs_emit() and sysfs_emit_at() accordingly, as the
> latter is aware of the PAGE_SIZE buffer and correctly returns the number
> of bytes written into the buffer.
> 
> No functional change intended.
[]
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
[]
> @@ -465,8 +465,8 @@ static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
>  
>  	entry = irq_get_msi_desc(irq);
>  	if (entry)
> -		return sprintf(buf, "%s\n",
> -				entry->msi_attrib.is_msix ? "msix" : "msi");
> +		return sysfs_emit(buf, "%s\n",
> +				  entry->msi_attrib.is_msix ? "msix" : "msi");
>  
> 
>  	return -ENODEV;
>  }

trivia: reversing the test would be more common style

	if (!entry)
		return -ENODEV;

	return sysfs_emit(...);
}
Krzysztof Wilczyński May 15, 2021, 6:01 a.m. UTC | #2
Hi Joe,

[...]
> >  	if (entry)
> > -		return sprintf(buf, "%s\n",
> > -				entry->msi_attrib.is_msix ? "msix" : "msi");
> > +		return sysfs_emit(buf, "%s\n",
> > +				  entry->msi_attrib.is_msix ? "msix" : "msi");
> >  
> > 
> >  	return -ENODEV;
> >  }
> 
> trivia: reversing the test would be more common style
> 
> 	if (!entry)
> 		return -ENODEV;
> 
> 	return sysfs_emit(...);
> }

Excellent point.  I will send v3 later that includes this style change.

Thank you!

Krzysztof
diff mbox series

Patch

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 217dc9f0231f..dbfec59dfe41 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -465,8 +465,8 @@  static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
 
 	entry = irq_get_msi_desc(irq);
 	if (entry)
-		return sprintf(buf, "%s\n",
-				entry->msi_attrib.is_msix ? "msix" : "msi");
+		return sysfs_emit(buf, "%s\n",
+				  entry->msi_attrib.is_msix ? "msix" : "msi");
 
 	return -ENODEV;
 }