[PATCH] ALSA: usb-audio: fix urb timeout with URB_ISO_ASAP flag

[Michael Wu]

When the loglevel is greater than 4, with a long messages printed on the
console while playing or recording audios, the usb controller may become
abnormal.
`usb 1-2: timeout: still 1 active urbs on EP #1`

Fix it by configuring the transfer_flags URB_ISO_ASAP flag.

Signed-off-by: Michael Wu <michael at allwinnertech.com>
---
 sound/usb/endpoint.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 310cd6fb0038..df9a91c2fc7d 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -1245,7 +1245,7 @@ static int data_ep_set_params(struct snd_usb_endpoint *ep)
 		if (!u->urb->transfer_buffer)
 			goto out_of_memory;
 		u->urb->pipe = ep->pipe;
-		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
+		u->urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
 		u->urb->interval = 1 << ep->datainterval;
 		u->urb->context = u;
 		u->urb->complete = snd_complete_urb;
@@ -1288,7 +1288,7 @@ static int sync_ep_set_params(struct snd_usb_endpoint *ep)
 		u->urb->transfer_dma = ep->sync_dma + i * 4;
 		u->urb->transfer_buffer_length = 4;
 		u->urb->pipe = ep->pipe;
-		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
+		u->urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
 		u->urb->number_of_packets = 1;
 		u->urb->interval = 1 << ep->syncinterval;
 		u->urb->context = u;
-- 
2.29.0