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jbeale
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PS3 Eye: "retire_capture_urb" what does this mean?

Tue Jul 19, 2016 4:49 pm

My PS3 Eye device is working OK on my Pi2B as an audio input, but I get a stream of messages in "dmesg" like "retire_capture_urb: 11 callbacks suppressed" one about every 10 seconds or so. I assume these are harmless given the system works as intended, but I'm curious what "retire_capture_urb" means, and how I can turn these messages off.

Description of my system: viewtopic.php?f=38&t=154642#p1011184
Same problem described back in 2012: viewtopic.php?f=38&t=15851#p180475

I found out what URB means from a description at http://www.makelinux.net/ldd3/chp-13-sect-3 :
The USB code in the Linux kernel communicates with all USB devices using something called a urb (USB request block).
but still I don't understand what all messages mean, is it a warning of some kind? I did find the Linux USB audio code below.
http://lxr.free-electrons.com/source/so ... cm.c#L1265

Code: Select all

/* Since a URB can handle only a single linear buffer, we must use double
1261  * buffering when the data to be transferred overflows the buffer boundary.
1262  * To avoid inconsistencies when updating hwptr_done, we use double buffering
1263  * for all URBs.
1264  */
1265 static void retire_capture_urb(struct snd_usb_substream *subs, struct urb *urb)

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MarkHaysHarris777
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Location: Rochester, MN
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Re: PS3 Eye: "retire_capture_urb" what does this mean?

Tue Jul 19, 2016 5:01 pm

Sometimes this message is received if you don't run as root...

... retry as root user (sudo) and see if the messages go away .

marcus
marcus
:ugeek:

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jbeale
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Re: PS3 Eye: "retire_capture_urb" what does this mean?

Wed Jul 20, 2016 3:19 am

thanks for the suggestion! It was worth a try, but running the command as root does not make any difference, I still get the spew.

Code: Select all

root       623 28.2  2.9  33036 11100 ?        S    20:17   0:16 ffmpeg -f alsa -ac 2 -ar 8000 -i plughw:1 -map 0:0 -acodec libmp3lame -b:a 64k -f segment -strftime 1 -segment_time 300 -segment_atclocktime 1 /home/pi/audio/ChA_%Y-%m-%d_%H-%M-%S.mp3

[   37.360542] retire_capture_urb: 2 callbacks suppressed
[   42.704270] retire_capture_urb: 11 callbacks suppressed
[   49.814220] retire_capture_urb: 9 callbacks suppressed
[   55.164839] retire_capture_urb: 5 callbacks suppressed
[   61.429721] retire_capture_urb: 2 callbacks suppressed
[   67.853663] retire_capture_urb: 2 callbacks suppressed
[   73.419353] retire_capture_urb: 11 callbacks suppressed

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jbeale
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Contact: Website

Re: PS3 Eye: "retire_capture_urb" what does this mean?

Wed Jul 20, 2016 6:22 pm

Additional information: based on these bug reports:
https://bugs.launchpad.net/ubuntu/+sour ... ug/1319457
https://github.com/raspberrypi/linux/issues/535
...this problem with the "retire_capture_urb" message cropped up in 2014 both in Raspbian, and also in Ubuntu linux-image-3.13.0-26-generic 3.13.0-26.48 when using USB audio devices. Both initial bug reports are closed as fixed, but apparently the fix was not completely successful, as post-"closed" comments to both bugs indicate the messages still occur, both in Raspbian and also Ubuntu.

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