The two methods appear to do the same, except hda-verb applies the change when run and the other method at the time the hda kernel module is loaded. You can run hda-verb at boot instead, but the other method looks cleaner to me, as it applies the fix when the hardware is configured by the driver. I believe this fix can also be added to the driver itself.
As I described above, after Hui Wang fixed this bug here that we're commenting on, I started to hear noise in headphones. This is not occasional crackling sound, this is constant annoying noise. Not every gen6 Carbon has this issue, apparently. This fixes the issue.  https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1805079/comments/8  https://lkml.org/lkml/2018/12/4/520 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1805079 Title: click/pop noise in the headphone on several lenovo laptops Status in linux package in Ubuntu: Fix Committed Bug description: [Impact] Lenovo told us that some linux uers reported headphone noise on Lenovo's website. After investigating, we found those Lenovo laptop mdoels all have the codec of alc285, and we can reproduce the noise problem too. [Fix] Don't use the DAC of headphone, let headphone share the DAC with speaker, the noise disappears. [Test Case] After applying this patch, we tested on Lenovo P52, P72, X1 carbon and X1 Yoda2, no noise anymore [Regression Potential] Low. This patch only apply to several lenovo machines, and after applying this patch, both speaker and headphone still work very well. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1805079/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : firstname.lastname@example.org Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp