Radeon error, kernel says No UMS support in radeon module

[Yovan]

A day ago i have edited ~/.config/pulse/client.conf with the following change:

; autospawn = yes

to

autospawn = no

Today i face Xorg error with the following message:
[drm] VGACON disable radeon kernel modesetting.
[drm:radeon_init [radeon]] *ERROR* No UMS support in radeon module!

If this change caused this error, please advise a better way to solve another bug "pulseaudio : Daemon already running" if the ~/.config/pulse/client.conf should remain as "; autospawn = yes".

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-101-generic 4.4.0-101.124
ProcVersionSignature: Ubuntu 4.4.0-101.124-generic 4.4.95
Uname: Linux 4.4.0-101-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.13
Architecture: amd64
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/by-path', '/dev/snd/hwC0D0', '/dev/snd/pcmC0D1p', '/dev/snd/pcmC0D0c', '/dev/snd/pcmC0D0p', '/dev/snd/controlC0', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
CurrentDesktop: Unity
Date: Wed Dec 6 12:40:24 2017
HibernationDevice: RESUME=UUID=c99260e9-9788-4bdd-89b4-89ed5f922889
InstallationDate: Installed on 2017-02-12 (296 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
MachineType: LENOVO 2768CJ6
ProcFB:

ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-101-generic root=UUID=a2edc425-72a2-40f7-be42-d78deda20ba5 ro recovery nomodeset
PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
 linux-restricted-modules-4.4.0-101-generic N/A
 linux-backports-modules-4.4.0-101-generic N/A
 linux-firmware 1.157.14
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/17/2012
dmi.bios.vendor: LENOVO
dmi.bios.version: 7UET94WW (3.24 )
dmi.board.name: 2768CJ6
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr7UET94WW(3.24):bd10/17/2012:svnLENOVO:pn2768CJ6:pvrThinkPadT400:rvnLENOVO:rn2768CJ6:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 2768CJ6
dmi.product.version: ThinkPad T400
dmi.sys.vendor: LENOVO

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.15 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.15-rc2

[Yovan (navoytak)]

Hi, the bug seems to be fixed by running "sudo update-initramfs -u" and correcting the BIOS configuration display setting from "Switchable Graphics" to "Discrete Graphics".

The PulseAudio Daemon message is gone and the radeon UMS message is gone.

The background of this is i have blacklisted i915 Intel Integrated Graphics by blacklisting it using "install i915 /bin/true". Thanks for the attention