hi Clements: I am sorry to bother you by sending this mail directly, since I found the mail I sent last night is rejected due to alsa-devel doesn't allow "Post by non-member to a members-only list"
except below #1 requirement I need your help, if I purposely want to sent fixed number of urbs by myself to easily debug, would you please tell me where I can modify the source code?
In my case, the default alsa seems use 8 urbs to repeat send/complete/....send/complete to quire data from ep. (my high-speed webcam has an enpoint with packet length 132, interval = 8 microframe ) Below is one of end point description. Endpoint Descriptor: bLength 9 bDescriptorType 5 bEndpointAddress 0x86 EP 6 IN bmAttributes 5 Transfer Type Isochronous Synch Type Asynchronous Usage Type Data wMaxPacketSize 0x0084 1x 132 bytes bInterval 4 bRefresh 0 bSynchAddress 0
If I want to use 2 urbs and only send/complete 1 round, would you please where I can find the source code to modify?
thanks for your kind help,
---------- Forwarded message ---------- From: vichy vichy.kuo@gmail.com Date: 2013/9/8 Subject: question about webcam audio capture To: linux-usb@vger.kernel.org, alsa-devel@alsa-project.org
hi all: I try to do webcam audio capture on my arm platform. when I execute audio capture I got below message "retire_capture_urb: 108 callbacks suppressed"
my questions: 1. where I can get the message "retire_capture_urb: 108 callbacks suppressed" show in sound/usb driver? I try to grep -rwn '"retire_capture_urb.*' sound/usb/*, but get nothing. what does "retire_capture_urb: 108 callbacks suppressed" mean?
2. from usb mon log, it seems HW keep Active status high even until ehci_io_watchdog happen, because the ep status is -EXDEV. if my observation is correct, is it possible to modify usb sound driver to purposely send fix number urbs. Because from the usb mon log, the first 8 urb will get time out already.
thanks for your help in advance,