[PATCH 24/41] ALSA: usb-audio: Fix EP matching for continuous rates

Takashi Iwai tiwai at suse.de
Mon Nov 23 09:53:30 CET 2020


The function to evaluate the match of the parameters with an EP
assumes only the discrete rate tables and doesn't handle the
continuous rates properly.

This patch fixes match_endpoint_audioformats() to handle the
continuous rates.  Also the almost useless debug prints there are
dropped.

Tested-by: Keith Milner <kamilner at superlative.org>
Tested-by: Dylan Robinson <dylan_robinson at motu.com>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/usb/pcm.c | 37 +++++++++++++------------------------
 1 file changed, 13 insertions(+), 24 deletions(-)

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index ac6385a4eb70..45a692512d27 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -695,41 +695,30 @@ static int match_endpoint_audioformats(struct snd_usb_substream *subs,
 				       struct audioformat *match, int rate,
 				       snd_pcm_format_t pcm_format)
 {
-	int i;
-	int score = 0;
+	int i, score;
 
-	if (fp->channels < 1) {
-		dev_dbg(&subs->dev->dev,
-			"%s: (fmt @%p) no channels\n", __func__, fp);
+	if (fp->channels < 1)
 		return 0;
-	}
 
-	if (!(fp->formats & pcm_format_to_bits(pcm_format))) {
-		dev_dbg(&subs->dev->dev,
-			"%s: (fmt @%p) no match for format %d\n", __func__,
-			fp, pcm_format);
+	if (!(fp->formats & pcm_format_to_bits(pcm_format)))
 		return 0;
-	}
 
-	for (i = 0; i < fp->nr_rates; i++) {
-		if (fp->rate_table[i] == rate) {
-			score++;
-			break;
+	if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS) {
+		if (rate < fp->rate_min || rate > fp->rate_max)
+			return 0;
+	} else {
+		for (i = 0; i < fp->nr_rates; i++) {
+			if (fp->rate_table[i] == rate)
+				break;
 		}
-	}
-	if (!score) {
-		dev_dbg(&subs->dev->dev,
-			"%s: (fmt @%p) no match for rate %d\n", __func__,
-			fp, rate);
-		return 0;
+		if (i >= fp->nr_rates)
+			return 0;
 	}
 
+	score = 1;
 	if (fp->channels == match->channels)
 		score++;
 
-	dev_dbg(&subs->dev->dev,
-		"%s: (fmt @%p) score %d\n", __func__, fp, score);
-
 	return score;
 }
 
-- 
2.16.4



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