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| author | Krzysztof Helt <krzysztof.h1@wp.pl> | 2009-12-19 18:31:04 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2009-12-21 12:02:55 +0100 |
| commit | 40962d7c741de1c21b6ce8516c1d9f8836fb383e (patch) | |
| tree | a8e520b5bb7062f108919475834155c152ff2cc8 /sound | |
| parent | ef86f581f7e8b29cb58d7f4e892e1a91b3805124 (diff) | |
| download | lwn-40962d7c741de1c21b6ce8516c1d9f8836fb383e.tar.gz lwn-40962d7c741de1c21b6ce8516c1d9f8836fb383e.zip | |
ALSA: fix incorrect rounding direction in snd_interval_ratnum()
The direction of rounding is incorrect in the snd_interval_ratnum()
It was detected with following parameters (sb8 driver playing
8kHz stereo file):
- num is always 1000000
- requested frequency rate is from 7999 to 7999 (single frequency)
The first loop calculates div_down(num, freq->min) which is 125.
Thus, a frequency range's minimum value is 1000000 / 125 = 8000 Hz.
The second loop calculates div_up(num, freq->max) which is 126
The frequency range's maximum value is 1000000 / 126 = 7936 Hz.
The range maximum is lower than the range minimum so the function
fails due to empty result range.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/core/pcm_lib.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 30f410832a25..a27545b23ee9 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -758,7 +758,7 @@ int snd_interval_ratnum(struct snd_interval *i, int diff; if (q == 0) q = 1; - den = div_down(num, q); + den = div_up(num, q); if (den < rats[k].den_min) continue; if (den > rats[k].den_max) @@ -794,7 +794,7 @@ int snd_interval_ratnum(struct snd_interval *i, i->empty = 1; return -EINVAL; } - den = div_up(num, q); + den = div_down(num, q); if (den > rats[k].den_max) continue; if (den < rats[k].den_min) |