This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- artful' to 'verification-done-artful'. If the problem still exists, change the tag 'verification-needed-artful' to 'verification-failed- artful'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: verification-needed-artful -- 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/1758800 Title: hda driver initialization takes too much time on the machine with coffeelake audio controller [8086:a348] Status in HWE Next: New Status in linux package in Ubuntu: Confirmed Status in linux-oem package in Ubuntu: New Status in linux source package in Xenial: Invalid Status in linux-oem source package in Xenial: Fix Committed Status in linux source package in Artful: Fix Committed Status in linux-oem source package in Artful: Invalid Bug description: [Impact] We have a couple of laptop and desktop computers, all of them are cfl platforms and all of them have cfl audio controller [8086:a348], and these computers have different realtek codecs on them (alc256, alc255, alc289 and ...). The hda driver takes too much time (3 secs - 8 secs) to initialize on these machines. This problem never happened on kbl, skl, bdw, ... before. Sometimes this can make pulseaudio can't work well. pulseaudio starts, but the driver (as kernel modules) initialization has not finished, then there is no valid sink in the pulseaudio. At this moment, some UI Apps already start using pulseaudio to play sound, but users can't hear the sound as expected. This problem never happened before, it is exposed on cfl platforms, and all cfl platforms (with audio controller 8086:a348) have this problem. [Fix] Set the polling mode can fix this problem, and this workaround is in the mainline kernel. [Test Case] Boot the machine and check the dmesg, from the hda log, we can see the driver initialization is finished within 0.1s and pulseaudio works well. [Regression Potential] No regression, this fix is only for CFL audio controller (8086:a348), and in theory, polling mode is safe for all audio controllers, using interrupt mode rather than polling mode on other platforms just wants to save polling overhead for CPUs, since interrupt mode can't work well on CFL platform, we have to use polling mode. To manage notifications about this bug go to: https://bugs.launchpad.net/hwe-next/+bug/1758800/+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