[PATCH] Signdness issue in drivers/video/intelfb/intelfbdrv.c

[PATCH] Signdness issue in drivers/video/intelfb/intelfbdrv.c

[Eric Sesterhenn]

hi,

another gcc 4.1 signess warning:

drivers/video/intelfb/intelfbdrv.c:419: warning: comparison of unsigned expression < 0 is always false

since dinfo->mtrr_reg is of the type u32, the error check dinfo->mtrr_reg < 0
is useless. This patch introduces a helper variable, which catches possible
negative error values returned by mtrr_add()

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>

--- linux-2.6.18-rc4/drivers/video/intelfb/intelfbdrv.c.orig	2006-08-20 20:46:11.000000000 +0200
+++ linux-2.6.18-rc4/drivers/video/intelfb/intelfbdrv.c	2006-08-20 20:47:14.000000000 +0200
@@ -414,12 +414,13 @@ module_exit(intelfb_exit);
 #ifdef CONFIG_MTRR
 static inline void __devinit set_mtrr(struct intelfb_info *dinfo)
 {
-	dinfo->mtrr_reg = mtrr_add(dinfo->aperture.physical,
+	int mtrr_reg = mtrr_add(dinfo->aperture.physical,
 				   dinfo->aperture.size, MTRR_TYPE_WRCOMB, 1);
-	if (dinfo->mtrr_reg < 0) {
+	if (mtrr_reg < 0) {
 		ERR_MSG("unable to set MTRR\n");
 		return;
 	}
+	dinfo->mtrr_reg = mtrr_reg;
 	dinfo->has_mtrr = 1;
 }
 static inline void unset_mtrr(struct intelfb_info *dinfo)

Re: [PATCH] Signdness issue in drivers/video/intelfb/intelfbdrv.c

[Dave Airlie]

On 8/21/06, Eric Sesterhenn <snakebyte@gmx.de> wrote:
> hi,
>
> another gcc 4.1 signess warning:
>
> drivers/video/intelfb/intelfbdrv.c:419: warning: comparison of unsigned expression < 0 is always false
>
> since dinfo->mtrr_reg is of the type u32, the error check dinfo->mtrr_reg < 0
> is useless. This patch introduces a helper variable, which catches possible
> negative error values returned by mtrr_add()
>
> Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
>

NAK.
I've applied a much simpler fix to use make mtrr_reg an int to my
intelfb tree....

Dave.