[alsa-devel] [PATCH] ALSA: usb-audio: Apply 48kHz fixed rate playback for Jabra Evolve 65 headset

[Takashi Iwai]

Jabra Evolve 65 headset appears as if supporting lower rates than
48kHz, but it actually doesn't work but with 48kHz for playback.

This patch applies a workaround to enforce the 48kHz like LINE6
devices already did.  The workaround is put in a unified helper
function, set_fixed_rate(), to be called from both places now.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=206149
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/usb/format.c | 33 ++++++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/sound/usb/format.c b/sound/usb/format.c
index 9260136e4c9b..50cb183958bf 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -151,6 +151,19 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
 	return pcm_formats;
 }
 
+static int set_fixed_rate(struct audioformat *fp, int rate, int rate_bits)
+{
+	kfree(fp->rate_table);
+	fp->rate_table = kmalloc(sizeof(int), GFP_KERNEL);
+	if (!fp->rate_table)
+		return -ENOMEM;
+	fp->nr_rates = 1;
+	fp->rate_min = rate;
+	fp->rate_max = rate;
+	fp->rates = rate_bits;
+	fp->rate_table[0] = rate;
+	return 0;
+}
 
 /*
  * parse the format descriptor and stores the possible sample rates
@@ -223,6 +236,14 @@ static int parse_audio_format_rates_v1(struct snd_usb_audio *chip, struct audiof
 		fp->rate_min = combine_triple(&fmt[offset + 1]);
 		fp->rate_max = combine_triple(&fmt[offset + 4]);
 	}
+
+	/* Jabra Evolve 65 headset */
+	if (chip->usb_id == USB_ID(0x0b0e, 0x030b)) {
+		/* only 48kHz for playback while keeping 16kHz for capture */
+		if (fp->nr_rates != 1)
+			return set_fixed_rate(fp, 48000, SNDRV_PCM_RATE_48000);
+	}
+
 	return 0;
 }
 
@@ -299,17 +320,7 @@ static int line6_parse_audio_format_rates_quirk(struct snd_usb_audio *chip,
 	case USB_ID(0x0e41, 0x4248): /* Line6 Helix >= fw 2.82 */
 	case USB_ID(0x0e41, 0x4249): /* Line6 Helix Rack >= fw 2.82 */
 	case USB_ID(0x0e41, 0x424a): /* Line6 Helix LT >= fw 2.82 */
-		/* supported rates: 48Khz */
-		kfree(fp->rate_table);
-		fp->rate_table = kmalloc(sizeof(int), GFP_KERNEL);
-		if (!fp->rate_table)
-			return -ENOMEM;
-		fp->nr_rates = 1;
-		fp->rate_min = 48000;
-		fp->rate_max = 48000;
-		fp->rates = SNDRV_PCM_RATE_48000;
-		fp->rate_table[0] = 48000;
-		return 0;
+		return set_fixed_rate(fp, 48000, SNDRV_PCM_RATE_48000);
 	}
 
 	return -ENODEV;
-- 
2.16.4