Commit 9f65df9c589f for kernel

commit 9f65df9c589f249435255da37a5dd11f1bc86f4d
Author: Geert Uytterhoeven <geert+renesas@glider.be>
Date:   Mon Jan 11 14:02:51 2021 +0100

    ALSA: firewire-tascam: Fix integer overflow in midi_port_work()

    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 / 31250

    always 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")
    Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
    Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
    Link: https://lore.kernel.org/r/20210111130251.361335-3-geert+renesas@glider.be
    Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/firewire/tascam/tascam-transaction.c b/sound/firewire/tascam/tascam-transaction.c
index 90288b4b4637..a073cece4a7d 100644
--- a/sound/firewire/tascam/tascam-transaction.c
+++ b/sound/firewire/tascam/tascam-transaction.c
@@ -209,7 +209,7 @@ static void midi_port_work(struct work_struct *work)

 	/* Set interval to next transaction. */
 	port->next_ktime = ktime_add_ns(ktime_get(),
-				port->consume_bytes * 8 * NSEC_PER_SEC / 31250);
+			port->consume_bytes * 8 * (NSEC_PER_SEC / 31250));

 	/* Start this transaction. */
 	port->idling = false;