ALSA: usb-audio: Do not expose PCM and DSD on same altsetting unless DoP

Do not expose DSD altsetting as a PCM one, even if the descriptor claims
it to be PCM instead of special format.

Signed-off-by: Jussi Laako <jussi@sonarnerd.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20251211152224.1780782-3-jussi@sonarnerd.net

Author: jlaako

sound/usb/format.c

@@ -34,6 +34,7 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
 {
 	int sample_width, sample_bytes;
 	u64 pcm_formats = 0;
+	u64 dsd_formats = 0;
 
 	switch (fp->protocol) {
 	case UAC_VERSION_1:
@@ -154,7 +155,9 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
 			 fp->iface, fp->altsetting, format);
 	}
 
-	pcm_formats |= snd_usb_interface_dsd_format_quirks(chip, fp, sample_bytes);
+	dsd_formats |= snd_usb_interface_dsd_format_quirks(chip, fp, sample_bytes);
+	if (dsd_formats && !fp->dsd_dop)
+		pcm_formats = dsd_formats;
 
 	return pcm_formats;
 }