simple mixer: fix calculation of control range

When calculating the value range of a control, the variables cannot be
initialized with zero because this would prevent the minimum from having
a value above zero or the maximum from having a value below zero.

diff --git a/src/mixer/simple_none.c b/src/mixer/simple_none.c
index 6b015af138cb7ea0527ad1f3b4852f81bbf3fc57..b490e1c1d3f552e6a4d8372f8dad4ac2fd2b2b77 100644 (file)
--- a/src/mixer/simple_none.c
+++ b/src/mixer/simple_none.c
@@ -37,6 +37,7 @@
 #include <sys/ioctl.h>
 #include <assert.h>
 #include <math.h>
+#include <limits.h>
 #include <alsa/asoundlib.h>
 #include "mixer_simple.h"
 
@@ -672,9 +673,11 @@ static int simple_update(snd_mixer_elem_t *melem)
 
        caps = 0;
        pchannels = 0;
-       pmin = pmax = 0;
+       pmin = LONG_MAX;
+       pmax = LONG_MIN;
        cchannels = 0;
-       cmin = cmax = 0;
+       cmin = LONG_MAX;
+       cmax = LONG_MIN;
        assert(snd_mixer_elem_get_type(melem) == SND_MIXER_ELEM_SIMPLE);
        simple = snd_mixer_elem_get_private(melem);
        name = snd_mixer_selem_get_name(melem);
@@ -868,13 +871,13 @@ static int simple_update(snd_mixer_elem_t *melem)
        simple->selem.caps = caps;
        simple->str[SM_PLAY].channels = pchannels;
        if (!simple->str[SM_PLAY].range) {
-               simple->str[SM_PLAY].min = pmin;
-               simple->str[SM_PLAY].max = pmax;
+               simple->str[SM_PLAY].min = pmin != LONG_MAX ? pmin : 0;
+               simple->str[SM_PLAY].max = pmax != LONG_MIN ? pmax : 0;
        }
        simple->str[SM_CAPT].channels = cchannels;
        if (!simple->str[SM_CAPT].range) {
-               simple->str[SM_CAPT].min = cmin;
-               simple->str[SM_CAPT].max = cmax;
+               simple->str[SM_CAPT].min = cmin != LONG_MAX ? cmin : 0;
+               simple->str[SM_CAPT].max = cmax != LONG_MIN ? cmax : 0;
        }
        return 0;
 }