Re: [PATCH] drivers: pci: This patch fix the following checkpatch warning.

From: Bjorn Helgaas
Date: Wed Apr 17 2019 - 17:35:47 EST


Hi Mohan,

On Tue, Apr 16, 2019 at 07:43:40PM +0300, Mohan Kumar wrote:
> Use pr_err instead of printk

I don't mind taking patches like these, but they do tend to clutter
the revision history if we're not careful. So here are some hints:

- Make the subject line useful. The one here really doesn't tell me
anything. Run "git log --oneline drivers/pci/bus.c" and follow
the conventions there. Something like:

PCI: Convert printk(KERN_*) to pr_*()

- Do all the similar changes at once. I notice similar things in
these files:

drivers/pci/pci-acpi.c
drivers/pci/pci-stub.c
drivers/pci/pci-sysfs.c
drivers/pci/pci.c
drivers/pci/pcie/aspm.c
drivers/pci/quirks.c
drivers/pci/setup-bus.c
drivers/pci/slot.c

plus several in drivers/pci/hotplug/. These could all be done in
a single patch.

- If there are several in a file that use the same prefix, add a
"#define pr_fmt()". This should be a separate patch so each patch
does only one type of change, which makes them easier to review.

- There are several uses of "printk(KERN_DEBUG)",
"dev_printk(KERN_DEBUG)", and "pci_printk(KERN_DEBUG)". The
obvious thing would be to convert those to pr_debug(), dev_dbg(),
and pci_dbg(), but I don't like that approach because pr_debug()
and friends do different things depending on how the kernel is
built. The uses in PCI provide information that I want to appear
in the dmesg log *always*. So they could be (a) left alone or (b)
converted from KERN_DEBUG to KERN_INFO (i.e., converted to
pr_info(), dev_info(), etc).

> WARNING: Prefer [subsystem eg: netdev]_err([subsystem]dev, ...
> then dev_err(dev, ... then pr_err(... to printk(KERN_ERR ...
>
> Signed-off-by: Mohan Kumar <mohankumar718@xxxxxxxxx>
> ---
> drivers/pci/bus.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
> index 5cb40b2..2179a8b 100644
> --- a/drivers/pci/bus.c
> +++ b/drivers/pci/bus.c
> @@ -23,7 +23,7 @@ void pci_add_resource_offset(struct list_head *resources, struct resource *res,
>
> entry = resource_list_create_entry(res, 0);
> if (!entry) {
> - printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res);
> + pr_err("PCI: can't add host bridge window %pR\n", res);
> return;
> }
>
> --
> 2.7.4
>