On Mon, Aug 20, 2018 at 8:59 AM Ran Shalit <[email protected]> wrote: > > Hello, > > We encounter the following strange behavior, and struggle with it for > couple of days now. I hope someone can suggest how to handle it. > > 1. We have a sound card, which takes ~100seconds(!) till it finishes > loading of snd-usb-audio module. > please see log here: > https://pastebin.com/raw/BbNgUvLw > As you can see the last line " usbcore: registered new interface > driver snd-usb-audio" is printed ~100 seconds after the card is > detected. > 2. Testing other sound cards in same system, shows normal behavior.
A little update, we haven't tested this yet, so it's not correct. We just saw on similar hw/kernel that there is no issue, but haven't test it yet on the problematic system. So this section should be ignored. > 3. Surprisingly, testing same sound card with another distribution > (ubuntu) shows no such behavior, and things are immediate. > 4. We already tried several kernels and see the same behavior in all > the tested kernels 3.18.11, 4.0.8 , 4.4.98. > 5. I did find similar issues described here, but no resolve is given: > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1537465 > > I would appreciate any suggestion, Is there a way to debug the reason for snd-usb-audio waiting time ? > ranran
