From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 6 Feb 2007 18:12:11 +0000 (+0100)
Subject: usbaudio - Fix Oops with broken usb descriptors
X-Git-Tag: v2.6.19.5~7
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=77a7080134c8136f995316c4963f7da2db39808d;p=thirdparty%2Fkernel%2Fstable.git

usbaudio - Fix Oops with broken usb descriptors

This is a patch for ALSA Bug #2724. Some webcams provide bogus
settings with no valid rates. With this patch those are skipped.

Signed-off-by: Gregor Jasny <gjasny@web.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index 88f3a94b83518..1d7685121550a 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -2456,6 +2456,7 @@ static int parse_audio_format_rates(struct snd_usb_audio *chip, struct audioform
 		 * build the rate table and bitmap flags
 		 */
 		int r, idx, c;
+		unsigned int nonzero_rates = 0;
 		/* this table corresponds to the SNDRV_PCM_RATE_XXX bit */
 		static unsigned int conv_rates[] = {
 			5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000,
@@ -2478,6 +2479,7 @@ static int parse_audio_format_rates(struct snd_usb_audio *chip, struct audioform
 			    fp->altsetting == 5 && fp->maxpacksize == 392)
 				rate = 96000;
 			fp->rate_table[r] = rate;
+			nonzero_rates |= rate;
 			if (rate < fp->rate_min)
 				fp->rate_min = rate;
 			else if (rate > fp->rate_max)
@@ -2493,6 +2495,10 @@ static int parse_audio_format_rates(struct snd_usb_audio *chip, struct audioform
 			if (!found)
 				fp->needs_knot = 1;
 		}
+		if (!nonzero_rates) {
+			hwc_debug("All rates were zero. Skipping format!\n");
+			return -1;
+		}
 		if (fp->needs_knot)
 			fp->rates |= SNDRV_PCM_RATE_KNOT;
 	} else {