On Fri, 19 Dec 2014 robtongue@xxxxxxxxx wrote: > Hello, I was told to email this to this list... I filed a kernel bug here: > > https://bugzilla.kernel.org/show_bug.cgi?id=90101 > > With the following content: > "I have done extensive testing on this issue, and basically on any kernel > version higher than or equal to 3.13, I am unable to use my USB Create > Soundblaster card. The issue seems related to the USB subsystem as it > works just fine in the USB3 ports. I did a kernel bisect between 3.12.0 and > 3.13.0, and the offending commit is > > d0ce5c6b9208c79fc725c578eebdeb5724faf17d > USB: EHCI: use a bandwidth-allocation table > > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d0ce5c6b9208c79fc725c578eebdeb5724faf17d > > What happens is video playback stutters very heavily and there is no sound > stream making it out the SPDIF port on the USB soundcard. I also tried with > the speaker-test application and get a "Broken pipe" error. > > $ speaker-test -D iec958:CARD=Pro,DEV=0 -c 2 -t wav > > speaker-test 1.0.28 > > Playback device is iec958:CARD=Pro,DEV=0 > Stream parameters are 48000Hz, S16_LE, 2 channels > WAV file(s) > Rate set to 48000Hz (requested 48000Hz) > Buffer size range from 96 to 262144 > Period size range from 48 to 131072 > Using max buffer size 262144 > Periods = 4 > Unable to set hw params for playback: Broken pipe > Setting of hwparams failed: Broken pipe > > If I move to the USB3 port it works as expected, so the issue is most > definitely on the USB2 side. > > The USB hardware is: > 00:1a.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset > Family USB Enhanced Host Controller #2 (rev 04) > Subsystem: Lenovo Device 3086 > Kernel driver in use: ehci-pci > > > The Soundblaster hardware is: > Bus 001 Device 004: ID 041e:30df Creative Technology, Ltd" You'll have to collect a bunch of additional information. I'd like to see the entry in /sys/kernel/debug/usb/devices that describes the sound card, and the contents of the files under /sys/kernel/debug/usb/ehci/0000:00:1a.0/. I'd also like to see the dmesg log for when you try the test program, and a usbmon trace as well. This will require CONFIG_DEBUG_FS, CONFIG_USB_DEBUG, and CONFIG_USB_MON to be enabled in the kernel configuration. Can you do all this under a 3.18 or 3.17 kernel? Alan Stern -- 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
