>> Reproduceable hung-task in snd_usb_pcm or usb-core >> in VM with Behringer device. >> >> Hello maintainers of usb, >> >> I found a reproduceable hung-task problem when trying to use Behringer >> "Uphoria" audio devices inside VMware workstation, on Debian-SID with >> kernel 5.7 or with 5.8-rc5 . Kernel-trace and USB IDs are included. >> >> Am I right to post here? > >Yes. > >> The problem occurs every time when accessing the devices. >> The problem does NOT occur with: >> - another sound device (griffin) >> - on native Linux on another machine > >What about when you use the problematic machine with native Linux? >That's really the most important case. I have run it with native Linux on the same AMD machine, and now it works. Tried both the USB2 and the USB3 ports. It still outputs these warnings when connecting: [ 205.639776] usb 1-6: new high-speed USB device number 8 using xhci_hcd [ 205.823725] usb 1-6: New USB device found, idVendor=1397, idProduct=0509, bcdDevice= 1.12 [ 205.823732] usb 1-6: New USB device strings: Mfr=1, Product=3, SerialNumber=0 [ 205.823736] usb 1-6: Product: UMC404HD 192k [ 205.823738] usb 1-6: Manufacturer: BEHRINGER [ 208.045722] xhci_hcd 0000:03:00.0: WARN: buffer overrun event for slot 7 ep 4 on endpoint [ 208.045844] xhci_hcd 0000:03:00.0: WARN: buffer overrun event for slot 7 ep 4 on endpoint [ 208.045969] xhci_hcd 0000:03:00.0: WARN: buffer overrun event for slot 7 ep 4 on endpoint [ 208.046094] xhci_hcd 0000:03:00.0: WARN: buffer overrun event for slot 7 ep 4 on endpoint [ 208.046468] retire_capture_urb: 3 callbacks suppressed But I cannot see the problem anymore. So the problem is related to VMware. But other devices, also audio, work in that VMware installation. > >> I cannot tell if it is a bug with VMware, the Behringer >> audio devices, >> or if this might point to a bug in snd_usb_pcm. > >If the device works on the same machine under native Linux then >most likely it is a problem in VMware. > >If it doesn't, the failure symptoms (a hang inside usb_kill_urb) >indicate a problem in the USB host controller hardware or driver, >not in snd_usb_pcm or the audio device. > >> If you have an idea what to try I can apply patches, >> rebuild kernel and try if an improvement works. > >Try booting from a "Live" distribution and see what happens, if you >don't want to install Linux on the test machine. > >Alan Stern Thanks for your answer! Achim.
