From: Chris Wulff <crwulff@xxxxxxxxx> [ 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@xxxxxxxxx> Link: https://lore.kernel.org/r/20200314165449.4086-3-crwulff@xxxxxxxxx Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- sound/usb/card.c | 12 ++++++++---- sound/usb/quirks.c | 14 ++++++++++++++ sound/usb/quirks.h | 3 +++ 3 files changed, 25 insertions(+), 4 deletions(-) diff --git a/sound/usb/card.c b/sound/usb/card.c index 2644a5ae2b757..6615734d29911 100644 --- 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 8b5bc809efd3f..a95fbdbfbd05f 100644 --- 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 a80e0ddd07364..dc02c9d80e991 100644 --- 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 */ -- 2.25.1
