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>
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 30f4108..a27545b2 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -758,7 +758,7 @@
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 @@
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)