[alsa-devel] [PATCH] ALSA: hda - fixup for the bass speaker on Lenovo Carbon X1 7th gen

[Benjamin Poirier]

On 2019/11/29 15:40 +0100, Jaroslav Kysela wrote:
> The auto-parser assigns the bass speaker to DAC3 (NID 0x06) which
> is without the volume control. I do not see a reason to use DAC2,
> because the shared output to all speakers produces the sufficient
> and well balanced sound. The stereo support is enough for this
> purpose (laptop).
> 
> Signed-off-by: Jaroslav Kysela <perex at perex.cz>
> ---
>  sound/pci/hda/patch_realtek.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)

This patch is now commit d2cd795c4ece ("ALSA: hda - fixup for the bass
speaker on Lenovo Carbon X1 7th gen"). There was then followup commit
86353aa70ed0 ("ALSA: hda/realtek - Add quirk for the bass speaker on
Lenovo Yoga X1 7th gen").

As a result of those, the maximum sound output level on my laptop
reduced to ~60% of what it used to be.

Moreover, the quirk name is inaccurate. I have a "ThinkPad X1 Carbon
7th" (as confirmed by dmidecode) and its audio device id is:
        Subsystem: Lenovo Cannon Point-LP High Definition Audio Controller [17aa:2292]
but the patches list:
	SND_PCI_QUIRK(0x17aa, 0x2292, "Thinkpad X1 Yoga 7th", ALC285_FIXUP_SPEAKER2_TO_DAC1),
	SND_PCI_QUIRK(0x17aa, 0x2293, "Thinkpad X1 Carbon 7th", ALC295_FIXUP_DISABLE_DAC3),
(notice the mixup of id 0x2292).

Applying the following diff brings the volume back to previous levels
and brings functional volume control:

diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 68832f52c1ad..ed41e3fb5566 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -7260,7 +7260,7 @@ static const struct snd_pci_quirk alc269_fixup_tbl[] = {
 	SND_PCI_QUIRK(0x17aa, 0x224c, "Thinkpad", ALC298_FIXUP_TPT470_DOCK),
 	SND_PCI_QUIRK(0x17aa, 0x224d, "Thinkpad", ALC298_FIXUP_TPT470_DOCK),
 	SND_PCI_QUIRK(0x17aa, 0x225d, "Thinkpad T480", ALC269_FIXUP_LIMIT_INT_MIC_BOOST),
-	SND_PCI_QUIRK(0x17aa, 0x2292, "Thinkpad X1 Yoga 7th", ALC285_FIXUP_SPEAKER2_TO_DAC1),
+	SND_PCI_QUIRK(0x17aa, 0x2292, "Thinkpad X1 Yoga 7th", ALC295_FIXUP_DISABLE_DAC3),
 	SND_PCI_QUIRK(0x17aa, 0x2293, "Thinkpad X1 Carbon 7th", ALC285_FIXUP_SPEAKER2_TO_DAC1),
 	SND_PCI_QUIRK(0x17aa, 0x30bb, "ThinkCentre AIO", ALC233_FIXUP_LENOVO_LINE2_MIC_HOTKEY),
 	SND_PCI_QUIRK(0x17aa, 0x30e2, "ThinkCentre AIO", ALC233_FIXUP_LENOVO_LINE2_MIC_HOTKEY),

I can send a patch to fix the problems for my laptop but then I don't
know what's up for other devices that built on
ALC285_FIXUP_SPEAKER2_TO_DAC1.