ALSA: firewire-lib: fix to check cycle continuity

commit 77ce96543b03f437c6b45f286d8110db2b6622a3 upstream.

The local helper function to compare the given pair of cycle count
evaluates them. If the left value is less than the right value, the
function returns negative value.

If the safe cycle is less than the current cycle, it is the case of
cycle lost. However, it is not currently handled properly.

This commit fixes the bug.

Cc: <stable@vger.kernel.org>
Fixes: 705794c53b00 ("ALSA: firewire-lib: check cycle continuity")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20240218033026.72577-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Takashi Sakamoto 2024-02-18 12:30:26 +09:00 committed by Greg Kroah-Hartman
parent 2caa605079
commit 22df6ff560

View File

@ -951,7 +951,7 @@ static int generate_tx_packet_descs(struct amdtp_stream *s, struct pkt_desc *des
// to the reason.
unsigned int safe_cycle = increment_ohci_cycle_count(next_cycle,
IR_JUMBO_PAYLOAD_MAX_SKIP_CYCLES);
lost = (compare_ohci_cycle_count(safe_cycle, cycle) > 0);
lost = (compare_ohci_cycle_count(safe_cycle, cycle) < 0);
}
if (lost) {
dev_err(&s->unit->device, "Detect discontinuity of cycle: %d %d\n",