Hello,
I'm getting the same issue reported by Joschi in May, but with a docked T540p. I can confirm that doing the following fixes the issue for me:
==== 8< ==== # cat <<EOF >/lib/firmware/t540p.fw [codec] 0x10ec0292 0x17aa2210 0
[pincfg] 0x16 0x21211010 0x19 0x21a11010 EOF
# cat <<EOF >/etc/modprobe.d/hda-intel.conf options snd-hda-intel patch=t540p.fw,t540p.fw,t540p.fw EOF
Then rmmod/modprobe the snd-hda-intel kernel module, or just reboot. ==== 8< ====
I can see http://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/?id=1c37c... which I presume resolves this problem for T440s and T440p users.
Please could an additional line, I'm guessing as follows, be added to sound/pci/hda/patch_realtek.c to include T540p users in this happy group?
+ SND_PCI_QUIRK(0x17aa, 0x2210, "Thinkpad T540p", ALC292_FIXUP_TPT440_DOCK),
Thanks!
Jim