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tuner_e4k: Fix closest_arr_idx 

The previous method tried to do clever stuff assuming the sequence is
sorted. Unfortunately:

1) this didn't really find the 'closest' match
2) this didn't work for the first or last interval
3) this didn't work for freq slightly above or below the last/first freq

All in all, it's easier to try them all.

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
This commit is contained in:
Sylvain Munaut 2012-03-29 23:35:36 +02:00
parent a95b61f397
commit 60d88b6ed2
1 changed files with 8 additions and 7 deletions
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15
firmware/src/tuner_e4k.c
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@ -152,19 +152,20 @@ static const uint32_t rf_filt_center_l[] = {
static int closest_arr_idx(const uint32_t *arr, unsigned int arr_size, uint32_t freq)
{
unsigned int i;
uint32_t last_delta = 0xffffffff;
unsigned int i, bi;
uint32_t best_delta = 0xffffffff;
/* iterate over the array containing an ordered list of the center
/* iterate over the array containing a list of the center
* frequencies, selecting the closest one */
for (i = 0; i < arr_size; i++) {
uint32_t delta = unsigned_delta(freq, arr[i]);
if (last_delta < delta)
return i-1;
last_delta = delta;
if (delta < best_delta) {
best_delta = delta;
bi = i;
}
}
return -ERANGE;
return bi;
}
/* return 4-bit index as to which RF filter to select */