CVS commit: src/sys/dev/pci/hdaudio

[Matthias Drochner]

Module Name:    src
Committed By:   drochner
Date:           Wed Sep  9 11:47:24 UTC 2009

Modified Files:
        src/sys/dev/pci/hdaudio: hdaudio_afg.c

Log Message:
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)


To generate a diff of this commit:
cvs rdiff -u -r1.9 -r1.10 src/sys/dev/pci/hdaudio/hdaudio_afg.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/dev/pci/hdaudio/hdaudio_afg.c
diff -u src/sys/dev/pci/hdaudio/hdaudio_afg.c:1.9 src/sys/dev/pci/hdaudio/hdaudio_afg.c:1.10
--- src/sys/dev/pci/hdaudio/hdaudio_afg.c:1.9	Wed Sep  9 01:39:51 2009
+++ src/sys/dev/pci/hdaudio/hdaudio_afg.c	Wed Sep  9 11:47:24 2009
@@ -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 <supp...@precedence.co.uk>
@@ -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;
 }