ALSA: usb-audio: Register card at the last interface

The USB-audio driver matches per interface, and as default, it
registers the card instance at the very first instance.  This can be a
problem for the devices that have multiple interfaces to be probed, as
the udev rule isn't applied properly for the later appearing
interfaces.  Although we introduced the delayed_register option and
the quirks for covering those shortcomings, it's nothing but a
workaround for specific devices.

This patch is an another attempt to fix the problem in a more generic
way.  Now the driver checks the whole USB device descriptor at the
very first time when an interface is attached to a sound card.  It
looks at each matching interface in the descriptor and remembers the
last matching one.  The snd_card_register() is invoked only when this
last interface is probed.

After this change, the quirks for the delayed registration become
superfluous, hence they are removed along with the patch.  OTOH, the
delayed_register option is still kept, as it might be useful for some
corner cases (e.g. a special driver overtakes the interface probe from
the standard driver, and the last interface probe may miss).

Link: https://lore.kernel.org/r/20220904161247.16461-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 0 insertions, 42 deletions

diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 194c75c45628..eadac586bcc8 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -2031,48 +2031,6 @@ void snd_usb_audioformat_attributes_quirk(struct snd_usb_audio *chip,
 }
 
 /*
- * registration quirk:
- * the registration is skipped if a device matches with the given ID,
- * unless the interface reaches to the defined one.  This is for delaying
- * the registration until the last known interface, so that the card and
- * devices appear at the same time.
- */
-
-struct registration_quirk {
-	unsigned int usb_id;	/* composed via USB_ID() */
-	unsigned int interface;	/* the interface to trigger register */
-};
-
-#define REG_QUIRK_ENTRY(vendor, product, iface) \
-	{ .usb_id = USB_ID(vendor, product), .interface = (iface) }
-
-static const struct registration_quirk registration_quirks[] = {
-	REG_QUIRK_ENTRY(0x0951, 0x16d8, 2),	/* Kingston HyperX AMP */
-	REG_QUIRK_ENTRY(0x0951, 0x16ed, 2),	/* Kingston HyperX Cloud Alpha S */
-	REG_QUIRK_ENTRY(0x0951, 0x16ea, 2),	/* Kingston HyperX Cloud Flight S */
-	REG_QUIRK_ENTRY(0x0ecb, 0x1f46, 2),	/* JBL Quantum 600 */
-	REG_QUIRK_ENTRY(0x0ecb, 0x1f47, 2),	/* JBL Quantum 800 */
-	REG_QUIRK_ENTRY(0x0ecb, 0x1f4c, 2),	/* JBL Quantum 400 */
-	REG_QUIRK_ENTRY(0x0ecb, 0x2039, 2),	/* JBL Quantum 400 */
-	REG_QUIRK_ENTRY(0x0ecb, 0x203c, 2),	/* JBL Quantum 600 */
-	REG_QUIRK_ENTRY(0x0ecb, 0x203e, 2),	/* JBL Quantum 800 */
-	{ 0 }					/* terminator */
-};
-
-/* return true if skipping registration */
-bool snd_usb_registration_quirk(struct snd_usb_audio *chip, int iface)
-{
-	const struct registration_quirk *q;
-
-	for (q = registration_quirks; q->usb_id; q++)
-		if (chip->usb_id == q->usb_id)
-			return iface < q->interface;
-
-	/* Register as normal */
-	return false;
-}
-
-/*
  * driver behavior quirk flags
  */
 struct usb_audio_quirk_flags_table {