[PATCH 2/7] backlight: apple_bl: use pr_debug/err instead of printk

[PATCH 2/7] backlight: apple_bl: use pr_debug/err instead of printk

[Jingoo Han]

This patch uses pr_debug/err instead of printk to allow dynamic debugging.
It also fixes checkpatch warnings as below:

WARNING: Prefer pr_debug(... to printk(KERN_DEBUG, ...
WARNING: Prefer pr_err(... to printk(KERN_ERR, ...

Cc: Matthew Garrett <mjg@redhat.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
---
 drivers/video/backlight/apple_bl.c |   16 ++++++----------
 1 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/video/backlight/apple_bl.c b/drivers/video/backlight/apple_bl.c
index ef5ca0d..9236e95 100644
--- a/drivers/video/backlight/apple_bl.c
+++ b/drivers/video/backlight/apple_bl.c
@@ -61,8 +61,7 @@ static int intel_chipset_send_intensity(struct backlight_device *bd)
 	int intensity = bd->props.brightness;
 
 	if (debug)
-		printk(KERN_DEBUG DRIVER "setting brightness to %d\n",
-		       intensity);
+		pr_debug("setting brightness to %d\n", intensity);
 
 	intel_chipset_set_brightness(intensity);
 	return 0;
@@ -77,8 +76,7 @@ static int intel_chipset_get_intensity(struct backlight_device *bd)
 	intensity = inb(0xb3) >> 4;
 
 	if (debug)
-		printk(KERN_DEBUG DRIVER "read brightness of %d\n",
-		       intensity);
+		pr_debug("read brightness of %d\n", intensity);
 
 	return intensity;
 }
@@ -108,8 +106,7 @@ static int nvidia_chipset_send_intensity(struct backlight_device *bd)
 	int intensity = bd->props.brightness;
 
 	if (debug)
-		printk(KERN_DEBUG DRIVER "setting brightness to %d\n",
-		       intensity);
+		pr_debug("setting brightness to %d\n", intensity);
 
 	nvidia_chipset_set_brightness(intensity);
 	return 0;
@@ -124,8 +121,7 @@ static int nvidia_chipset_get_intensity(struct backlight_device *bd)
 	intensity = inb(0x52f) >> 4;
 
 	if (debug)
-		printk(KERN_DEBUG DRIVER "read brightness of %d\n",
-		       intensity);
+		pr_debug("read brightness of %d\n", intensity);
 
 	return intensity;
 }
@@ -150,7 +146,7 @@ static int __devinit apple_bl_add(struct acpi_device *dev)
 	host = pci_get_bus_and_slot(0, 0);
 
 	if (!host) {
-		printk(KERN_ERR DRIVER "unable to find PCI host\n");
+		pr_err("unable to find PCI host\n");
 		return -ENODEV;
 	}
 
@@ -162,7 +158,7 @@ static int __devinit apple_bl_add(struct acpi_device *dev)
 	pci_dev_put(host);
 
 	if (!hw_data) {
-		printk(KERN_ERR DRIVER "unknown hardware\n");
+		pr_err("unknown hardware\n");
 		return -ENODEV;
 	}
 
-- 
1.7.1

Re: [PATCH 2/7] backlight: apple_bl: use pr_debug/err instead of printk

[Andrew Morton]

On Tue, 15 May 2012 16:52:50 +0900
Jingoo Han <jg1.han@samsung.com> wrote:

> This patch uses pr_debug/err instead of printk to allow dynamic debugging.
> It also fixes checkpatch warnings as below:
> 
> WARNING: Prefer pr_debug(... to printk(KERN_DEBUG, ...
> WARNING: Prefer pr_err(... to printk(KERN_ERR, ...
> 
> ...
>
> --- a/drivers/video/backlight/apple_bl.c
> +++ b/drivers/video/backlight/apple_bl.c
> @@ -61,8 +61,7 @@ static int intel_chipset_send_intensity(struct backlight_device *bd)
>  	int intensity = bd->props.brightness;
>  
>  	if (debug)
> -		printk(KERN_DEBUG DRIVER "setting brightness to %d\n",
> -		       intensity);
> +		pr_debug("setting brightness to %d\n", intensity);

This looks wrong.  It replaces

	apple_backlight: setting brightness to 42

with

	setting brightness to 42

To do this properly we should do

#define pf_fmt "apple_backlight: "

before including printk.h.  Conventionally this is done before
including any headers.

Also, apple_bl.c should explicitly include printk.h.

If doing this, please remove the DRIVER #define altogether.



Please check all the other drivers in this patchset.  If they already
have custom things like DRIVER then remove that, define pr_fmt then
convert all the messages.

In other words, I'm recommending a functional change.  For example,
drivers/video/backlight/generic_bl.c currently prints

	Generic Backlight Driver Initialized

and I'm recommending that we switch this to

	generic_bl: Generic Backlight Driver Initialized