[src/trunk]: src/sys/dev/pci/hdaudio catch the case where a mixer's "step" va...

[drochner <drochner%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a530365d7397
branches:  trunk
changeset: 747308:a530365d7397
user:      drochner <drochner%NetBSD.org@localhost>
date:      Wed Sep 09 11:47:24 2009 +0000

description:
catch the case where a mixer's "step" value is 0 (read from the hardware),
while such a mixer is likely not very useful it should not cause
a division by 0
(should fix the crash reported by Tobias Nygren)

diffstat:

 sys/dev/pci/hdaudio/hdaudio_afg.c |  28 ++++++++++++++++++----------
 1 files changed, 18 insertions(+), 10 deletions(-)

diffs (71 lines):

diff -r 6baa8c61865e -r a530365d7397 sys/dev/pci/hdaudio/hdaudio_afg.c
--- a/sys/dev/pci/hdaudio/hdaudio_afg.c Wed Sep 09 10:38:35 2009 +0000
+++ b/sys/dev/pci/hdaudio/hdaudio_afg.c Wed Sep 09 11:47:24 2009 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: hdaudio_afg.c,v 1.9 2009/09/09 01:39:51 jmcneill Exp $ */
+/* $NetBSD: hdaudio_afg.c,v 1.10 2009/09/09 11:47:24 drochner Exp $ */
 
 /*
  * Copyright (c) 2009 Precedence Technologies Ltd <support%precedence.co.uk@localhost>
@@ -60,7 +60,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: hdaudio_afg.c,v 1.9 2009/09/09 01:39:51 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: hdaudio_afg.c,v 1.10 2009/09/09 11:47:24 drochner Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -3355,7 +3355,7 @@
        struct hdaudio_afg_softc *sc = ad->ad_sc;
        struct hdaudio_mixer *mx;
        struct hdaudio_control *ctl;
-       int i;
+       int i, divisor;
 
        if (mc->dev < 0 || mc->dev >= sc->sc_nmixers)
                return EINVAL;
@@ -3385,9 +3385,14 @@
                return 0;
        }
 
+       if (ctl->ctl_step == 0)
+               divisor = 128; /* ??? - just avoid div by 0 */
+       else
+               divisor = 255 / ctl->ctl_step;
+
        hdaudio_afg_control_amp_set(ctl, HDAUDIO_AMP_MUTE_NONE,
-         mc->un.value.level[AUDIO_MIXER_LEVEL_LEFT] / (255 / ctl->ctl_step),
-         mc->un.value.level[AUDIO_MIXER_LEVEL_RIGHT] / (255 / ctl->ctl_step));
+         mc->un.value.level[AUDIO_MIXER_LEVEL_LEFT] / divisor,
+         mc->un.value.level[AUDIO_MIXER_LEVEL_RIGHT] / divisor);
            
        return 0;
 }
@@ -3400,7 +3405,7 @@
        struct hdaudio_mixer *mx;
        struct hdaudio_control *ctl;
        u_int mask = 0;
-       int i;
+       int i, factor;
 
        if (mc->dev < 0 || mc->dev >= sc->sc_nmixers)
                return EINVAL;
@@ -3430,10 +3435,13 @@
                return 0;
        }
 
-       mc->un.value.level[AUDIO_MIXER_LEVEL_LEFT] =
-                       ctl->ctl_left * (255 / ctl->ctl_step);
-       mc->un.value.level[AUDIO_MIXER_LEVEL_RIGHT] =
-                       ctl->ctl_right * (255 / ctl->ctl_step);
+       if (ctl->ctl_step == 0)
+               factor = 128; /* ??? - just avoid div by 0 */
+       else
+               factor = 255 / ctl->ctl_step;
+
+       mc->un.value.level[AUDIO_MIXER_LEVEL_LEFT] = ctl->ctl_left * factor;
+       mc->un.value.level[AUDIO_MIXER_LEVEL_RIGHT] = ctl->ctl_right * factor;
        return 0;
 }