ALSA: usb-audio: Add QUIRK_FLAG_SKIP_IFACE_SETUP

[ Upstream commit 38c3220 ]

Add a quirk flag to skip the usb_set_interface(),
snd_usb_init_pitch(), and snd_usb_init_sample_rate() calls in
__snd_usb_parse_audio_interface(). These are redundant with
snd_usb_endpoint_prepare() at stream-open time.

Enable the quirk for Focusrite devices, as init_sample_rate(rate_max)
sets 192kHz during probing, which disables the internal mixer and Air
and Safe modes.

Fixes: 16f1f83 ("Revert "ALSA: usb-audio: Drop superfluous interface setup at parsing"")
Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/65a7909b15f9feb76c2a6f4f8814c240ddc50737.1771594828.git.g@b4.vu
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: geoffreybennett

sound/usb/quirks.c

@@ -2422,7 +2422,7 @@ static const struct usb_audio_quirk_flags_table quirk_flags_table[] = {
 	VENDOR_FLG(0x07fd, /* MOTU */
 		   QUIRK_FLAG_VALIDATE_RATES),
 	VENDOR_FLG(0x1235, /* Focusrite Novation */
-		   0),
+		   QUIRK_FLAG_SKIP_IFACE_SETUP),
 	VENDOR_FLG(0x1511, /* AURALiC */
 		   QUIRK_FLAG_DSD_RAW),
 	VENDOR_FLG(0x152a, /* Thesycon devices */
@@ -2504,6 +2504,7 @@ static const char *const snd_usb_audio_quirk_flag_names[] = {
 	QUIRK_STRING_ENTRY(MIC_RES_384),
 	QUIRK_STRING_ENTRY(MIXER_PLAYBACK_MIN_MUTE),
 	QUIRK_STRING_ENTRY(MIXER_CAPTURE_MIN_MUTE),
+	QUIRK_STRING_ENTRY(SKIP_IFACE_SETUP),
 	NULL
 };
 

sound/usb/stream.c

@@ -1259,6 +1259,9 @@ static int __snd_usb_parse_audio_interface(struct snd_usb_audio *chip,
 			set_iface_first = true;
 
 		/* try to set the interface... */
+		if (chip->quirk_flags & QUIRK_FLAG_SKIP_IFACE_SETUP)
+			continue;
+
 		usb_set_interface(chip->dev, iface_no, 0);
 		if (set_iface_first)
 			usb_set_interface(chip->dev, iface_no, altno);

sound/usb/usbaudio.h

@@ -224,6 +224,10 @@ extern bool snd_usb_skip_validation;
  *  playback value represents muted state instead of minimum audible volume
  * QUIRK_FLAG_MIXER_CAPTURE_MIN_MUTE
  *  Similar to QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE, but for capture streams
+ * QUIRK_FLAG_SKIP_IFACE_SETUP
+ *  Skip the probe-time interface setup (usb_set_interface,
+ *  init_pitch, init_sample_rate); redundant with
+ *  snd_usb_endpoint_prepare() at stream-open time
  */
 
 enum {
@@ -253,6 +257,7 @@ enum {
 	QUIRK_TYPE_MIC_RES_384			= 23,
 	QUIRK_TYPE_MIXER_PLAYBACK_MIN_MUTE	= 24,
 	QUIRK_TYPE_MIXER_CAPTURE_MIN_MUTE	= 25,
+	QUIRK_TYPE_SKIP_IFACE_SETUP		= 26,
 /* Please also edit snd_usb_audio_quirk_flag_names */
 };
 
@@ -284,5 +289,6 @@ enum {
 #define QUIRK_FLAG_MIC_RES_384			QUIRK_FLAG(MIC_RES_384)
 #define QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE	QUIRK_FLAG(MIXER_PLAYBACK_MIN_MUTE)
 #define QUIRK_FLAG_MIXER_CAPTURE_MIN_MUTE	QUIRK_FLAG(MIXER_CAPTURE_MIN_MUTE)
+#define QUIRK_FLAG_SKIP_IFACE_SETUP		QUIRK_FLAG(SKIP_IFACE_SETUP)
 
 #endif /* __USBAUDIO_H */