[PATCH] staging/udlfb: Fix sparse warning 'Using plain integer as NULL pointer'

[PATCH] staging/udlfb: Fix sparse warning 'Using plain integer as NULL pointer'

[Peter Huewe]

This patch fixes the warning generated by sparse: "Using plain integer
as NULL pointer" by replacing the offending 0s with NULL.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
---
KernelVersion: linux-next-20101207

 drivers/staging/udlfb/udlfb.c |   14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/udlfb/udlfb.c b/drivers/staging/udlfb/udlfb.c
index 8dd21e0..6586d38 100644
--- a/drivers/staging/udlfb/udlfb.c
+++ b/drivers/staging/udlfb/udlfb.c
@@ -395,10 +395,10 @@ static void dlfb_compress_hline(
 
 	while ((pixel_end > pixel) &&
 	       (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
-		uint8_t *raw_pixels_count_byte = 0;
-		uint8_t *cmd_pixels_count_byte = 0;
-		const uint16_t *raw_pixel_start = 0;
-		const uint16_t *cmd_pixel_start, *cmd_pixel_end = 0;
+		uint8_t *raw_pixels_count_byte = NULL;
+		uint8_t *cmd_pixels_count_byte = NULL;
+		const uint16_t *raw_pixel_start = NULL;
+		const uint16_t *cmd_pixel_start, *cmd_pixel_end = NULL;
 
 		prefetchw((void *) cmd); /* pull in one cache line at least */
 
@@ -1277,7 +1277,7 @@ static int dlfb_setup_modes(struct dlfb_data *dev,
 	/* If everything else has failed, fall back to safe default mode */
 	if (default_vmode == NULL) {
 
-		struct fb_videomode fb_vmode = {0};
+		struct fb_videomode fb_vmode = {NULL};
 
 		/*
 		 * Add the standard VESA modes to our modelist
@@ -1533,8 +1533,8 @@ static int dlfb_usb_probe(struct usb_interface *interface,
 			const struct usb_device_id *id)
 {
 	struct usb_device *usbdev;
-	struct dlfb_data *dev = 0;
-	struct fb_info *info = 0;
+	struct dlfb_data *dev = NULL;
+	struct fb_info *info = NULL;
 	int retval = -ENOMEM;
 	int i;
 
-- 
1.7.2.2

Re: [PATCH] staging/udlfb: Fix sparse warning 'Using plain integer as NULL pointer'

[Dan Carpenter]

On Tue, Dec 07, 2010 at 11:16:41PM +0100, Peter Huewe wrote:
>  	while ((pixel_end > pixel) &&
>  	       (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
> -		uint8_t *raw_pixels_count_byte = 0;
> -		uint8_t *cmd_pixels_count_byte = 0;
> -		const uint16_t *raw_pixel_start = 0;
> -		const uint16_t *cmd_pixel_start, *cmd_pixel_end = 0;
> +		uint8_t *raw_pixels_count_byte = NULL;
> +		uint8_t *cmd_pixels_count_byte = NULL;
> +		const uint16_t *raw_pixel_start = NULL;
> +		const uint16_t *cmd_pixel_start, *cmd_pixel_end = NULL;
>  

It would be better to delete these.  The assignments are pointless and
may well end up generating warnings in future versions of gcc.  (Maybe
it already does with beta versions of gcc?)

> -		struct fb_videomode fb_vmode = {0};
> +		struct fb_videomode fb_vmode = {NULL};

Just do this:
		struct fb_videomode fb_vmode = {};

>  	struct usb_device *usbdev;
> -	struct dlfb_data *dev = 0;
> -	struct fb_info *info = 0;
> +	struct dlfb_data *dev = NULL;
> +	struct fb_info *info = NULL;
>  	int retval = -ENOMEM;
>  	int i;

You could leave dev uninitialized here again.

regards,
dan carpenter