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hwmon: (lm85) Fix function RANGE_TO_REG() 

Function RANGE_TO_REG() is broken. For a requested range of 2000 (2
degrees C), it will return an index value of 15, i.e. 80.0 degrees C,
instead of the expected index value of 0. All other values are handled
properly, just 2000 isn't.

The bug was introduced back in November 2004 by this patch:
http://git.kernel.org/?p=linux/kernel/git/tglx/history.git;a=commit;h=1c28d80f1992240373099d863e4996cdd5d646d0

While this can be fixed easily with the current code, I'd rather
rewrite the whole function in a way which is more obviously correct.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Justin Thiessen <jthiessen@penguincomputing.com>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
This commit is contained in:
Jean Delvare 2008-04-03 10:40:39 +02:00 committed by Mark M. Hoffman
parent 5dd34572ad
commit d38b149794
1 changed files with 11 additions and 14 deletions
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25
drivers/hwmon/lm85.c
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@ -192,23 +192,20 @@ static int RANGE_TO_REG( int range )
{
int i;
if ( range < lm85_range_map[0] ) {
return 0 ;
} else if ( range > lm85_range_map[15] ) {
if (range >= lm85_range_map[15])
return 15 ;
} else { /* find closest match */
for ( i = 14 ; i >= 0 ; --i ) {
if ( range > lm85_range_map[i] ) { /* range bracketed */
if ((lm85_range_map[i+1] - range) <
(range - lm85_range_map[i])) {
i++;
break;
}
break;
}
/* Find the closest match */
for (i = 14; i >= 0; --i) {
if (range >= lm85_range_map[i]) {
if ((lm85_range_map[i + 1] - range) <
(range - lm85_range_map[i]))
return i + 1;
return i;
}
}
return( i & 0x0f );
return 0;
}
#define RANGE_FROM_REG(val) (lm85_range_map[(val)&0x0f])