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authorTakashi Sakamoto <o-takashi@sakamocchi.jp>2019-02-26 13:38:37 +0900
committerTakashi Iwai <tiwai@suse.de>2019-02-26 07:11:40 +0100
commitf97a0944a72b26a2bece72516294e112a890f98a (patch)
treeff5aa5f7bd785b85df3c16128320b32af8c8eb63
parent7dc661bd8d3261053b69e4e2d0050cd1ee540fc1 (diff)
ALSA: firewire-motu: fix construction of PCM frame for capture direction
In data blocks of common isochronous packet for MOTU devices, PCM frames are multiplexed in a shape of '24 bit * 4 Audio Pack', described in IEC 61883-6. The frames are not aligned to quadlet. For capture PCM substream, ALSA firewire-motu driver constructs PCM frames by reading data blocks byte-by-byte. However this operation includes bug for lower byte of the PCM sample. This brings invalid content of the PCM samples. This commit fixes the bug. Reported-by: Peter Sjöberg <autopeter@gmail.com> Cc: <stable@vger.kernel.org> # v4.12+ Fixes: 4641c9394010 ("ALSA: firewire-motu: add MOTU specific protocol layer") Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r--sound/firewire/motu/amdtp-motu.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/sound/firewire/motu/amdtp-motu.c b/sound/firewire/motu/amdtp-motu.c
index f0555a24d90e..6c9b743ea74b 100644
--- a/sound/firewire/motu/amdtp-motu.c
+++ b/sound/firewire/motu/amdtp-motu.c
@@ -136,7 +136,9 @@ static void read_pcm_s32(struct amdtp_stream *s,
byte = (u8 *)buffer + p->pcm_byte_offset;
for (c = 0; c < channels; ++c) {
- *dst = (byte[0] << 24) | (byte[1] << 16) | byte[2];
+ *dst = (byte[0] << 24) |
+ (byte[1] << 16) |
+ (byte[2] << 8);
byte += 3;
dst++;
}