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

[Joe Perches]

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(...);
}