On Tue, 8 Nov 2016 sonofagun@xxxxxxxxxxxxxxx wrote: > My C-Media USB speakers do not work on Ubuntu 16.10 with 4.8.0 on my AMD > KABINI USB 2.0 port. Using Ubuntu 16.04 with 4.4.0 on the same machine > at the same port with the same cable fixes the issue. > If I put the speakers on any USB 3.0 connector then it works both in > 16.10 and 16.04!! > > Why do I get a different driver on the same port with a different > kernel? Good question. I don't know the answer; it may be hidden in a part of the system log that you didn't post. > Here is what gets logged normally, > > on Ubuntu 16.10: > [ 50.252683] usb 4-1: new full-speed USB device number 2 using > ohci-pci > [ 50.438712] usb 4-1: New USB device found, idVendor=0d8c, > idProduct=0103 > [ 50.438719] usb 4-1: New USB device strings: Mfr=1, Product=2, > SerialNumber=0 > [ 50.438725] usb 4-1: Product: C-Media USB Audio > [ 50.438731] usb 4-1: Manufacturer: C-Media INC. > [ 50.542693] usb 4-1: Warning! Unlikely big volume range (=9472), > cval->res is probably wrong. > [ 50.542700] usb 4-1: [13] FU [PCM Playback Volume] ch = 2, val = > -9473/-1/1 > [ 50.543246] usbcore: registered new interface driver snd-usb-audio > [ 62.867422] ohci-pci 0000:00:13.0: HcDoneHead not written back; > disabled > [ 62.867435] ohci-pci 0000:00:13.0: HC died; cleaning up > [ 62.867489] usb 4-1: USB disconnect, device number 2 This is a known bug in the 4.8 kernel, caused by changes to the timer code. A workaround and a proper fix have both been added to the 4.9-rc series and will be part of the next 4.8.stable release. Alan Stern > on Ubuntu 16.04: > [ 1168.662575] usb 7-4: new full-speed USB device number 4 using > xhci_hcd > [ 1168.833911] usb 7-4: New USB device found, idVendor=0d8c, > idProduct=0103 > [ 1168.833921] usb 7-4: New USB device strings: Mfr=1, Product=2, > SerialNumber=0 > [ 1168.833927] usb 7-4: Product: C-Media USB Audio > [ 1168.833931] usb 7-4: Manufacturer: C-Media INC. > [ 1168.867900] usb 7-4: Warning! Unlikely big volume range (=9472), > cval->res is probably wrong. > [ 1168.867910] usb 7-4: [13] FU [PCM Playback Volume] ch = 2, val = > -9473/-1/1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
