15.05.2014 04:20, Dan MacDonald wrote:
Hi list
I have got HDMI audio out to kinda work but the sound quality is awful and not really listenable. Its very choppy and is slightly more high-pitched than it should be. This is when using hdmi:CARD=HDMI,DEV=1 @48khz outputting via ALSA 1.0.27.2 / jackd 0.124.2 under Deb Jessie amd64 with kernel 3.13.10-1. Its a System76 Gazelle Pro laptop FWIW.
This may be another manifestation of https://bugzilla.kernel.org/show_bug.cgi?id=60769 which is still not completely fixed but has a workaround.
For me, it leads to silence, for others, it leads to underruns and screeching sounds. Please test whether appending this kernel command line option helps:
intel_iommu=on,igfx_off
$ lspci -v:
00:03.0 Audio device: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor HD Audio Controller (rev 06) Subsystem: CLEVO/KAPOK Computer Device 0655 Flags: bus master, fast devsel, latency 0, IRQ 49 Memory at f7e14000 (64-bit, non-prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: snd_hda_intel
00:1b.0 Audio device: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller (rev 05)
Subsystem: CLEVO/KAPOK Computer Device0655
Flags: bus master, fast devsel, latency 0, IRQ48
Memory at f7e10000 (64-bit, non-prefetchable)[size=16K]
Capabilities: <accessdenied>
Kernel driver in use: snd_hda_intel$ cat /proc/asound/card0/codec#0 Codec: Intel Haswell HDMI Address: 0 AFG Function Id: 0x1 (unsol 0) Vendor Id: 0x80862807 Subsystem Id: 0x80860101 Revision Id: 0x100000