[ALSA] mpu401 - Add MPU401_INFO_UART_ONLY bitflag

Added MPU401_INFO_UART_ONLY bitflag to avoid issueing UART_ENTER command
at opening streams.  Some devices support only UART mode and give errors
to UART_ENTER.
A new module option, uart_enter, is added to snd-mpu401 driver.
For UART-only devices, set uart_enter=0.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 1 insertions, 0 deletions

diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt
index 73e9a174b642..24ea129969ae 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -1278,6 +1278,7 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
     port        - port number or -1 (disable)
     irq         - IRQ number or -1 (disable)
     pnp         - PnP detection - 0 = disable, 1 = enable (default)
+    uart_enter  - Issue UART_ENTER command at open - bool, default = on
 
     This module supports multiple devices and PnP.