On Mon, 11 Jan 2021 14:02:51 +0100, Geert Uytterhoeven wrote:
As snd_fw_async_midi_port.consume_bytes is unsigned int, and NSEC_PER_SEC is 1000000000L, the second multiplication in
port->consume_bytes * 8 * NSEC_PER_SEC / 31250always overflows on 32-bit platforms, truncating the result. Fix this by precalculating "NSEC_PER_SEC / 31250", which is an integer constant.
Note that this assumes port->consume_bytes <= 16777.
Fixes: 531f471834227d03 ("ALSA: firewire-lib/firewire-tascam: localize async midi port") Signed-off-by: Geert Uytterhoeven geert+renesas@glider.be
Compile-tested only.
I don't know the maximum transfer length of MIDI, but given it's an old standard, I guess it's rather small. If it is larger than 16777, the constant "8" should be replaced by "8ULL", to force 64-bit arithmetic.
Applied now. Thanks.
Takashi