Re: ALSA: hda_intel - revert a quirk that affect VIA chipsets

[Takashi Iwai <tiwai@suse.de>]

At Tue, 29 Nov 2011 12:21:17 +0100,
Marc Vertes wrote:
> 
> This quirk sould be reverted. It has the following probems:
> 
> 1) The quirk was intended to "ASUS MV2-MX SE" motherboards only, but the
> ID used matches a much broader range, potentially all boards containing a
> VIA chipset model in the family of vendor VIA 0x1106 and audio device ID
> 0x3288, which encompasses VIA-VT82xx, VIA-VT1xx and VIA-VT20xx chipsets.
> 
> 2) VIA chipsets rely on azx_via_get_position() to handle correctly dma
> transfers during capture. Using POS_FIX_LPIB instead of POS_FIX_VIACOMBO
> leads to partially corrupted input buffers during capture. The effects
> of this bug are not immediately visible, it took strong DSP expertise,
> some expensive signal generator and a spectrum analyzer to identify it
> and verify correct behaviour using original default.
> 
> 3) It's almost certain that the quirk did not fix the real problem,
> if there was one. Refer to original submission:
> http://mailman.alsa-project.org/pipermail/alsa-devel/2010-February/025109.html
> 
> Signed-of-by: Marc Vertes <mvertes@sigfox.com>

Applied now.  Thanks.


Takashi

> 
> --- linux-3.2-rc3/sound/pci/hda/hda_intel.c.orig	2011-11-24 05:20:28.000000000 +0100
> +++ linux-3.2-rc3/sound/pci/hda/hda_intel.c	2011-11-28 17:29:01.044095455 +0100
> @@ -2508,7 +2508,6 @@ static struct snd_pci_quirk position_fix
>  	SND_PCI_QUIRK(0x1043, 0x81b3, "ASUS", POS_FIX_LPIB),
>  	SND_PCI_QUIRK(0x1043, 0x81e7, "ASUS M2V", POS_FIX_LPIB),
>  	SND_PCI_QUIRK(0x104d, 0x9069, "Sony VPCS11V9E", POS_FIX_LPIB),
> -	SND_PCI_QUIRK(0x1106, 0x3288, "ASUS M2V-MX SE", POS_FIX_LPIB),
>  	SND_PCI_QUIRK(0x1297, 0x3166, "Shuttle", POS_FIX_LPIB),
>  	SND_PCI_QUIRK(0x1458, 0xa022, "ga-ma770-ud3", POS_FIX_LPIB),
>  	SND_PCI_QUIRK(0x1462, 0x1002, "MSI Wind U115", POS_FIX_LPIB),
>