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authorTakashi Iwai <tiwai@suse.de>2018-05-02 10:04:27 +0200
committerTakashi Iwai <tiwai@suse.de>2018-05-02 16:02:33 +0200
commit8a463225b11047455b374729d18c8a371fe6e591 (patch)
treead4bfb774497805fc775abf7c64ec7169c2c2919 /sound/usb/usbaudio.h
parentb099b9693d23d035c77c218508e083484ff63024 (diff)
ALSA: usb-audio: Add keep_iface flag
Introduce a new flag to struct snd_usb_audio for allowing the device to skip usb_set_interface() calls at changing or closing the stream. As of this patch, the flag is nowhere set, so it's just a place holder. The dynamic switching will be added in the following patch. A background information for this change: Dell WD15 dock with Realtek chip gives a very long pause at each time the driver changes the altset, which eventually happens at every PCM stream open/close and parameter change. As the long pause happens in each usb_set_interface() call, there is nothing we can do as long as it's called. The workaround is to reduce calling it as much as possible, and this flag indicates that behavior. Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/usbaudio.h')
-rw-r--r--sound/usb/usbaudio.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index 4d5c89a7ba2b..32f4a5425536 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -59,6 +59,9 @@ struct snd_usb_audio {
int setup; /* from the 'device_setup' module param */
bool autoclock; /* from the 'autoclock' module param */
+ bool keep_iface; /* keep interface/altset after closing
+ * or parameter change
+ */
struct usb_host_interface *ctrl_intf; /* the audio control interface */
};