Public bug reported: When using the combination of modesetting Xorg driver with Intel GVT-g enabled, it was observed problems with brightness control.
While the brightness control still has functionality, it works with significant delay for every change. Every change takes roughly half a second, making the change from zero to full brightness using the keyboard shortcuts take more than 10 seconds. The brightness keys are buffered too, making it hard to reach intermediate values. The attached video show the problem being reproduced using xfce4-power- manager notification on the xfce4-panel. This problem wasn't observed when using the Intel Xorg driver and this problem doesn't happen if modesetting is used without iGVT-g. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: xserver-xorg-core 2:1.20.7-2ubuntu2 ProcVersionSignature: Ubuntu 5.4.0-21.25-generic 5.4.27 Uname: Linux 5.4.0-21-generic x86_64 NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair ApportVersion: 2.20.11-0ubuntu21 Architecture: amd64 BootLog: CompositorRunning: None Date: Wed Apr 1 21:02:21 2020 DistUpgraded: 2019-12-22 18:50:28,852 DEBUG Running PostInstallScript: './xorg_fix_proprietary.py' DistroCodename: focal DistroVariant: ubuntu ExtraDebuggingInterest: Yes, if not too technical GraphicsCard: Intel Corporation Skylake GT2 [HD Graphics 520] [8086:1916] (rev 07) (prog-if 00 [VGA controller]) Subsystem: Lenovo Skylake GT2 [HD Graphics 520] [17aa:3822] InstallationDate: Installed on 2017-06-13 (1023 days ago) InstallationMedia: Xubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412) MachineType: LENOVO 80UG ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-21-generic root=UUID=6b4ae5c0-c78c-49a6-a1ba-029192618a7a ro quiet ro kvm.ignore_msrs=1 kvm.report_ignored_msrs=0 kvm.halt_poll_ns=0 kvm.halt_poll_ns_grow=0 i915.enable_gvt=1 resume=UUID=a82e38a0-8d20-49dd-9cbd-de7216b589fc log_buf_len=16M usbhid.quirks=0x0079:0x0006:0x100000 mtrr_gran_size=64M mtrr_chunk_size=64M nbd.nbds_max=2 nbd.max_part=63 SourcePackage: xorg-server UpgradeStatus: Upgraded to focal on 2019-12-22 (101 days ago) dmi.bios.date: 08/09/2018 dmi.bios.vendor: LENOVO dmi.bios.version: 0XCN45WW dmi.board.asset.tag: NO Asset Tag dmi.board.name: Toronto 4A2 dmi.board.vendor: LENOVO dmi.board.version: SDK0J40679 WIN dmi.chassis.asset.tag: NO Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Lenovo ideapad 310-14ISK dmi.modalias: dmi:bvnLENOVO:bvr0XCN45WW:bd08/09/2018:svnLENOVO:pn80UG:pvrLenovoideapad310-14ISK:rvnLENOVO:rnToronto4A2:rvrSDK0J40679WIN:cvnLENOVO:ct10:cvrLenovoideapad310-14ISK: dmi.product.family: IDEAPAD dmi.product.name: 80UG dmi.product.sku: LENOVO_MT_80UG_BU_idea_FM_Lenovo ideapad 310-14ISK dmi.product.version: Lenovo ideapad 310-14ISK dmi.sys.vendor: LENOVO mtime.conffile..etc.apport.crashdb.conf: 2019-08-29T08:39:36.787240 version.compiz: compiz N/A version.libdrm2: libdrm2 2.4.100-4 version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.2-1ubuntu1 version.libgl1-mesa-glx: libgl1-mesa-glx 20.0.2-1ubuntu1 version.xserver-xorg-core: xserver-xorg-core 2:1.20.7-2ubuntu2 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.6-1 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20190815-1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1 ** Affects: xorg-server (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug focal ubuntu -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1870250 Title: Brightness control works in a inconsistent manner using modesetting Status in xorg-server package in Ubuntu: New Bug description: When using the combination of modesetting Xorg driver with Intel GVT-g enabled, it was observed problems with brightness control. While the brightness control still has functionality, it works with significant delay for every change. Every change takes roughly half a second, making the change from zero to full brightness using the keyboard shortcuts take more than 10 seconds. The brightness keys are buffered too, making it hard to reach intermediate values. The attached video show the problem being reproduced using xfce4 -power-manager notification on the xfce4-panel. This problem wasn't observed when using the Intel Xorg driver and this problem doesn't happen if modesetting is used without iGVT-g. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: xserver-xorg-core 2:1.20.7-2ubuntu2 ProcVersionSignature: Ubuntu 5.4.0-21.25-generic 5.4.27 Uname: Linux 5.4.0-21-generic x86_64 NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair ApportVersion: 2.20.11-0ubuntu21 Architecture: amd64 BootLog: CompositorRunning: None Date: Wed Apr 1 21:02:21 2020 DistUpgraded: 2019-12-22 18:50:28,852 DEBUG Running PostInstallScript: './xorg_fix_proprietary.py' DistroCodename: focal DistroVariant: ubuntu ExtraDebuggingInterest: Yes, if not too technical GraphicsCard: Intel Corporation Skylake GT2 [HD Graphics 520] [8086:1916] (rev 07) (prog-if 00 [VGA controller]) Subsystem: Lenovo Skylake GT2 [HD Graphics 520] [17aa:3822] InstallationDate: Installed on 2017-06-13 (1023 days ago) InstallationMedia: Xubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412) MachineType: LENOVO 80UG ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-21-generic root=UUID=6b4ae5c0-c78c-49a6-a1ba-029192618a7a ro quiet ro kvm.ignore_msrs=1 kvm.report_ignored_msrs=0 kvm.halt_poll_ns=0 kvm.halt_poll_ns_grow=0 i915.enable_gvt=1 resume=UUID=a82e38a0-8d20-49dd-9cbd-de7216b589fc log_buf_len=16M usbhid.quirks=0x0079:0x0006:0x100000 mtrr_gran_size=64M mtrr_chunk_size=64M nbd.nbds_max=2 nbd.max_part=63 SourcePackage: xorg-server UpgradeStatus: Upgraded to focal on 2019-12-22 (101 days ago) dmi.bios.date: 08/09/2018 dmi.bios.vendor: LENOVO dmi.bios.version: 0XCN45WW dmi.board.asset.tag: NO Asset Tag dmi.board.name: Toronto 4A2 dmi.board.vendor: LENOVO dmi.board.version: SDK0J40679 WIN dmi.chassis.asset.tag: NO Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Lenovo ideapad 310-14ISK dmi.modalias: dmi:bvnLENOVO:bvr0XCN45WW:bd08/09/2018:svnLENOVO:pn80UG:pvrLenovoideapad310-14ISK:rvnLENOVO:rnToronto4A2:rvrSDK0J40679WIN:cvnLENOVO:ct10:cvrLenovoideapad310-14ISK: dmi.product.family: IDEAPAD dmi.product.name: 80UG dmi.product.sku: LENOVO_MT_80UG_BU_idea_FM_Lenovo ideapad 310-14ISK dmi.product.version: Lenovo ideapad 310-14ISK dmi.sys.vendor: LENOVO mtime.conffile..etc.apport.crashdb.conf: 2019-08-29T08:39:36.787240 version.compiz: compiz N/A version.libdrm2: libdrm2 2.4.100-4 version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.2-1ubuntu1 version.libgl1-mesa-glx: libgl1-mesa-glx 20.0.2-1ubuntu1 version.xserver-xorg-core: xserver-xorg-core 2:1.20.7-2ubuntu2 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.6-1 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20190815-1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1870250/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp