[alsa-devel] Regression: very quiet speakers on Thinkpad T570s

[Takashi Iwai]

On Fri, 30 Nov 2018 17:51:33 +0100,
Jeremy Cline wrote:
> 
> On 11/30/18 11:00 AM, Takashi Iwai wrote:
> > On Fri, 30 Nov 2018 15:49:17 +0100,
> > Jeremy Cline wrote:
> >>
> >> Hi,
> >>
> >> Some folks have reported on the Fedora bug tracker[0] that the laptop
> >> speaker volume is very low on the Thinkpad T570 when running a kernel
> >> that includes commit 61fcf8ece9b6 ("ALSA: hda/realtek - Enable Thinkpad
> >> Dock device for ALC298 platform").
> >>
> >> alsa-info.sh from v4.15.4 (just before commit 61fcf8ece9b6 arrived in
> >> stable) and v4.19.4 with the issue present are attached to the bugzilla.
> >> I've also Cc'd Tim, who uploaded them and has the laptop in question.
> >>
> >> [0] https://bugzilla.redhat.com/show_bug.cgi?id=1554304
> > 
> > Could you pinpoint which kernel version started showing the
> > regression, at least?  The diffs are fairly wide between 4.15 and
> > 4.19.
> 
> Ah, sorry for not being more clear. The regression appears to be
> introduced by commit 61fcf8ece9b6, which got backported to v4.15.5
> because it addressed a bug with the dock[0]. v4.19.4 with that commit
> reverted works, according to the bug reporter.
> 
> [0] https://bugzilla.kernel.org/show_bug.cgi?id=195161

OK, then this seems to be the change of DAC assignment.

Maybe the hardware has some implicit assumption of NID 0x03 bound with
the speaker pin.  Below is a patch for fixing the pin / DAC mapping.
Please give it a try.


thanks,

Takashi

---
diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 06f93032d0cc..50bc2e97d799 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -4988,9 +4988,14 @@ static void alc_fixup_tpt470_dock(struct hda_codec *codec,
 		{ 0x19, 0x21a11010 }, /* dock mic */
 		{ }
 	};
+	static hda_nid_t preferred_pairs[] = {
+		0x14, 0x03, 0x17, 0x02, 0x21, 0x02,
+		0
+	};
 	struct alc_spec *spec = codec->spec;
 
 	if (action == HDA_FIXUP_ACT_PRE_PROBE) {
+		spec->gen.preferred_dacs = preferred_pairs;
 		spec->parse_flags = HDA_PINCFG_NO_HP_FIXUP;
 		snd_hda_apply_pincfgs(codec, pincfgs);
 	} else if (action == HDA_FIXUP_ACT_INIT) {