Public bug reported: On laptops with Kaby Lake processors and Sunrise point chipsets (System76 Lemu7), updating to the current (1.157.5) version of the linux-firmware package and then updating initramfs causes sound issues. This can manifest in two ways:
1: Volume hotkeys and controls appear to work, but actual playback volume remains the same. Three HDMI devices appear in the sound-settings gui, despite no HDMI device connected (and only 1 HDMI port) 2: 'Dummy Output' is the only device in the sound-settings gui, and there is no sound output at all. In both cases dmesg shows error output relating to snd_hda_codec_hdmi. This bug only affects Xenial, not Yakkety. Xenial still exhibits the above symptoms after installing the current Yakkety linux-firmware package. I believe the issue is related to the Kaby Lake firmware. In testing, I was able to remove '/lib/firmware/i915/kbl_dmc_ver1_01.bin', run 'sudo update-initramfs -u', and reboot to get sound working correctly again. Perhaps this firmware is needed for the upcoming Union Point chipsets, but causes problems with the for Kaby Lake processor laptops running the 4.4.0 kernel and Sunrise Point chipsets. There is either a bug in the new Kaby Lake firmware or it is being erroneously applied to inappropriate hardware. I have received a number of reports of users running into this bug, presumably anyone who updated to the latest kernel and linux-firmware packages at the same time. Based on testing, next kernel update could trigger the bug for many more users. ** Affects: linux-firmware (Ubuntu) Importance: Undecided Status: New ** Tags: kabylake linux-firmware sound update-initramfs -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1645911 Title: linux-firmware package causes sound issues with after initramfs update To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1645911/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs