Bug 47461

Summary: Intel HD: Sound is distorted
Product: Drivers Reporter: Ralf (post+kernel)
Component: Sound(ALSA)Assignee: Takashi Iwai (tiwai)
Status: RESOLVED CODE_FIX    
Severity: normal CC: florian, tiwai
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 3.6-rc5 Subsystem:
Regression: Yes Bisected commit-id:
Attachments: Fix patch

Description Ralf 2012-09-13 12:47:02 UTC
Using the vanilla 3.6-rc5 kernel with my Debian Wheezy system, sound is distorted: One can still recognize the sound that's supposed to be played in the distortion though. Unfortunately I don't know how to properly describe what I hear in English, please let me know if a recording would be helpful.
I am using PulseAudio as sound system. The distortion happens both with KDE system sounds and when using VLC.
Using the 3.2 kernel from Debian or a self-compiled vanilla 3.5.3 (and all the same userspace), sound playback is crystal clear, so this is a regression in 3.6. I can do a bisect, but I'd appreciate if someone could tell me to which directory it should be restricted - reporting this against the sound drivers is just a pure guess.

All this is on an Asus X53SM. The relevant part of the lspci -v output is:

00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 05)
        Subsystem: ASUSTeK Computer Inc. Device 1ac3
        Flags: bus master, fast devsel, latency 0, IRQ 49
        Memory at df000000 (64-bit, non-prefetchable) [size=16K]
        Capabilities: [50] Power Management version 2
        Capabilities: [60] MSI: Enable+ Count=1/1 Maskable- 64bit+
        Capabilities: [70] Express Root Complex Integrated Endpoint, MSI 00
        Capabilities: [100] Virtual Channel
        Capabilities: [130] Root Complex Link
        Kernel driver in use: snd_hda_intel
Comment 1 Takashi Iwai 2012-09-13 12:53:18 UTC
Try to pass position_fix=2 to snd-hda-intel module.

There was a similar bug report with ASUS K53E, and choosing this option helped.
Comment 2 Ralf 2012-09-13 13:16:48 UTC
Indeed this option seems to help. Thanks!

What does that mean now? Is this still a bug, or will this quirk be used automatically on affected HW?
Comment 3 Takashi Iwai 2012-09-13 13:31:05 UTC
We need a new quirk entry.

Could you try the patch below, remove position_fix option again, and see whether it works?
Comment 4 Takashi Iwai 2012-09-13 13:31:37 UTC
Created attachment 80081 [details]
Fix patch
Comment 5 Ralf 2012-09-13 14:19:18 UTC
Looking good so far. The path did not apply cleanly though as I don't have the ASUS K53E line.
Also, it may be more appropriate to use "ASUS X53S" as name for the quirk: I think the entire X53S series is very similar, and the big sticker on the laptop also just says "X53S".

Thanks for your quick replies!
Comment 6 Takashi Iwai 2012-09-13 14:59:06 UTC
OK, now I applied the patch (with "X53S" correction) to for-linus branch so that it'll be merged to Linus tree at the next pull request.
Comment 7 Takashi Iwai 2012-09-13 15:00:29 UTC
Let's close the bug now.
Please reopen if you see any problem with this fix.
Comment 8 Florian Mickler 2012-09-19 22:15:37 UTC
A patch referencing this bug report has been merged in Linux v3.6-rc6:

commit 64f1e00d8edb54f5d25fb0114a46050fb8340df4
Author: Takashi Iwai <tiwai@suse.de>
Date:   Thu Sep 13 15:28:56 2012 +0200

    ALSA: hda - Yet another position_fix quirk for ASUS machines