Hi Alexander
I have tried booting with just
intel_iommu=on,igfx_off
and also with
snd_hda_intel.align_buffer_size=1
but neither combination did anything to fix the garbled HDMI sound under both 3.13.10 (Deb Jessie) and 3.11.0 (Ubuntu 12.04.4). The analogue audio works fine.
On Thu, May 15, 2014 at 9:31 AM, Alexander E. Patrakov patrakov@gmail.comwrote:
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
-- Alexander E. Patrakov