[ALSA] Add MPU401_INFO_NO_ACK bitflag

Added MPU401_INFO_NO_ACK bitflag to ignore the ACK check for UART
commands. VT172x doesn't handle ACK commands, for example.

Tested-by: Pavel Hofman <[e-mail]>
Signed-off-by: Takashi Iwai <[e-mail]>

include/sound/mpu401.h

···
 #define MPU401_INFO_INTEGRATED	(1 << 2)	/* integrated h/w port */
 #define MPU401_INFO_MMIO	(1 << 3)	/* MMIO access */
 #define MPU401_INFO_TX_IRQ	(1 << 4)	/* independent TX irq */
+#define MPU401_INFO_NO_ACK	(1 << 6)	/* No ACK cmd needed */
 
 #define MPU401_MODE_BIT_INPUT		0
 #define MPU401_MODE_BIT_OUTPUT		1

sound/drivers/mpu401/mpu401_uart.c

···
 #endif
 	}
 	mpu->write(mpu, cmd, MPU401C(mpu));
-	if (ack) {
+	if (ack && !(mpu->info_flags & MPU401_INFO_NO_ACK)) {
 		ok = 0;
 		timeout = 10000;
 		while (!ok && timeout-- > 0) {

sound/pci/ice1712/ice1724.c

···
 			if ((err = snd_mpu401_uart_new(card, 0, MPU401_HW_ICE1712,
 						       ICEREG1724(ice, MPU_CTRL),
 						       (MPU401_INFO_INTEGRATED |
+							MPU401_INFO_NO_ACK |
 							MPU401_INFO_TX_IRQ),
 						       ice->irq, 0,
 						       &ice->rmidi[0])) < 0) {