diff mbox series

ALSA: usb-audio: fix urb timeout with URB_ISO_ASAP flag

Message ID 20221122082040.48591-1-michael@allwinnertech.com (mailing list archive)
State New, archived
Headers show
Series ALSA: usb-audio: fix urb timeout with URB_ISO_ASAP flag | expand

Commit Message

Michael Wu Nov. 22, 2022, 8:20 a.m. UTC
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@allwinnertech.com>
---
 sound/usb/endpoint.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Michael Wu Nov. 22, 2022, 8:54 a.m. UTC | #1
On 11/22/2022 4:46 PM, Takashi Iwai wrote:
> On Tue, 22 Nov 2022 09:20:40 +0100,
> Michael Wu wrote:
>>
>> 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@allwinnertech.com>
> 
> Hrm, that's somewhat backward action to the change we've done years
> ago, commit c75c5ab575af7db707689cdbb5a5c458e9a034bb:
> 
>      ALSA: USB: adjust for changed 3.8 USB API
>      
>      The recent changes in the USB API ("implement new semantics for
>      URB_ISO_ASAP") made the former meaning of the URB_ISO_ASAP flag the
>      default, and changed this flag to mean that URBs can be delayed.
>      This is not the behaviour wanted by any of the audio drivers because
>      it leads to discontinuous playback with very small period sizes.
>      Therefore, our URBs need to be submitted without this flag.
> 
> I rather suspect that your problem is in the USB controller side.
> 
> 
> thanks,
> 
> Takashi
> 
Dear Takashi, thanks for the reminding. Let me check...
diff mbox series

Patch

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;