From 1b7ecc241a67ad6b584e071bd791a54e0cd5f097 Mon Sep 17 00:00:00 2001 From: Hector Martin Date: Mon, 10 Aug 2020 17:24:00 +0900 Subject: ALSA: usb-audio: work around streaming quirk for MacroSilicon MS2109 Further investigation of the L-R swap problem on the MS2109 reveals that the problem isn't that the channels are swapped, but rather that they are swapped and also out of phase by one sample. In other words, the issue is actually that the very first frame that comes from the hardware is a half-frame containing only the right channel, and after that everything becomes offset. So introduce a new quirk field to drop the very first 2 bytes that come in after the format is configured and a capture stream starts. This puts the channels in phase and in the correct order. Cc: stable@vger.kernel.org Signed-off-by: Hector Martin Link: https://lore.kernel.org/r/20200810082400.225858-1-marcan@marcan.st Signed-off-by: Takashi Iwai --- sound/usb/stream.c | 1 + 1 file changed, 1 insertion(+) (limited to 'sound/usb/stream.c') diff --git a/sound/usb/stream.c b/sound/usb/stream.c index 4d1e6579e54d..ca76ba5b5c0b 100644 --- a/sound/usb/stream.c +++ b/sound/usb/stream.c @@ -94,6 +94,7 @@ static void snd_usb_init_substream(struct snd_usb_stream *as, subs->tx_length_quirk = as->chip->tx_length_quirk; subs->speed = snd_usb_get_speed(subs->dev); subs->pkt_offset_adj = 0; + subs->stream_offset_adj = 0; snd_usb_set_pcm_ops(as->pcm, stream); -- cgit v1.2.3