From: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx> commit 1be4f21d9984fa9835fae5411a29465dc5aece6f upstream. The quadlets for CIP header is handled as a part of IR context header, thus it doesn't join in IR context payload. However current calculation includes the quadlets in IR context payload. Cc: <stable@xxxxxxxxxxxxxxx> Fixes: f11453c7cc01 ("ALSA: firewire-lib: use 16 bytes IR context header to separate CIP header") Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210513125652.110249-5-o-takashi@xxxxxxxxxxxxx Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- sound/firewire/amdtp-stream.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) --- a/sound/firewire/amdtp-stream.c +++ b/sound/firewire/amdtp-stream.c @@ -1068,23 +1068,22 @@ static int amdtp_stream_start(struct amd s->data_block_counter = 0; } - /* initialize packet buffer */ + // initialize packet buffer. + max_ctx_payload_size = amdtp_stream_get_max_payload(s); if (s->direction == AMDTP_IN_STREAM) { dir = DMA_FROM_DEVICE; type = FW_ISO_CONTEXT_RECEIVE; - if (!(s->flags & CIP_NO_HEADER)) + if (!(s->flags & CIP_NO_HEADER)) { + max_ctx_payload_size -= 8; ctx_header_size = IR_CTX_HEADER_SIZE_CIP; - else + } else { ctx_header_size = IR_CTX_HEADER_SIZE_NO_CIP; - - max_ctx_payload_size = amdtp_stream_get_max_payload(s) - - ctx_header_size; + } } else { dir = DMA_TO_DEVICE; type = FW_ISO_CONTEXT_TRANSMIT; ctx_header_size = 0; // No effect for IT context. - max_ctx_payload_size = amdtp_stream_get_max_payload(s); if (!(s->flags & CIP_NO_HEADER)) max_ctx_payload_size -= IT_PKT_HEADER_SIZE_CIP; }