ALSA: usb-audio: Create a registration quirk for Kingston HyperX Amp (0951:16d8)

[ Upstream commit 55f7326170d9e83e2d828591938e1101982a679c ]

Create a quirk that allows special processing and/or
skipping the call to snd_card_register.

For HyperX AMP, which uses two interfaces, but only has
a capture stream in the second, this allows the capture
stream to merge with the first PCM.

Signed-off-by: Chris Wulff <crwulff@gmail.com>
Link: https://lore.kernel.org/r/20200314165449.4086-3-crwulff@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/sound/usb/card.c b/sound/usb/card.c
index 2644a5ae2b757bdd1e8cbb2fb6b009f5ef441fed..6615734d29911ad511b109f05740d7c8b02671fa 100644 (file)
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -668,10 +668,14 @@ static int usb_audio_probe(struct usb_interface *intf,
                        goto __error;
        }
 
-       /* we are allowed to call snd_card_register() many times */
-       err = snd_card_register(chip->card);
-       if (err < 0)
-               goto __error;
+       /* we are allowed to call snd_card_register() many times, but first
+        * check to see if a device needs to skip it or do anything special
+        */
+       if (snd_usb_registration_quirk(chip, ifnum) == 0) {
+               err = snd_card_register(chip->card);
+               if (err < 0)
+                       goto __error;
+       }
 
        usb_chip[chip->index] = chip;
        chip->num_interfaces++;

diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 8b5bc809efd3f0991ed0afec696767ebdc7c6bb5..a95fbdbfbd05f2112fcda5e599915dd7c7682ef2 100644 (file)
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -1508,3 +1508,17 @@ void snd_usb_audioformat_attributes_quirk(struct snd_usb_audio *chip,
                break;
        }
 }
+
+int snd_usb_registration_quirk(struct snd_usb_audio *chip,
+                              int iface)
+{
+       switch (chip->usb_id) {
+       case USB_ID(0x0951, 0x16d8): /* Kingston HyperX AMP */
+               /* Register only when we reach interface 2 so that streams can
+                * merge correctly into PCMs from interface 0
+                */
+               return (iface != 2);
+       }
+       /* Register as normal */
+       return 0;
+}

diff --git a/sound/usb/quirks.h b/sound/usb/quirks.h
index a80e0ddd07364603ab2462e17664c743f8c4ce18..dc02c9d80e9916c2e7dcebd5dee50b880fb81520 100644 (file)
--- a/sound/usb/quirks.h
+++ b/sound/usb/quirks.h
@@ -46,4 +46,7 @@ void snd_usb_audioformat_attributes_quirk(struct snd_usb_audio *chip,
                                          struct audioformat *fp,
                                          int stream);
 
+int snd_usb_registration_quirk(struct snd_usb_audio *chip,
+                              int iface);
+
 #endif /* __USBAUDIO_QUIRKS_H */