编辑：将内核升级到 4.11-rc2 解决了该问题。
我在联想 Thinkpad L460 上安装了全新的 Ubuntu Gnome。似乎无法通过 DP 将外接显示器连接到 4K 模式。FullHD 和 WQHD 似乎可以工作。
有人建议尝试安装 4.4.8-040408-generic。没有用。还安装了 intel-microcode 专有驱动程序。
当我尝试将显示屏的分辨率提高到 4K 时，显示器被禁用。以下内容打印到系统日志中：
Sep 7 10:46:10 juho-ThinkPad-L460 wpa_supplicant[2686]: wlp3s0: Failed to initiate sched scan
Sep 7 10:46:10 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[3011]: (II) intel(0): resizing framebuffer to 3840x3240
Sep 7 10:46:10 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[3011]: (II) intel(0): switch to mode [email protected] on DP1 using pipe 0, position (0, 0), rotation normal, reflection none
Sep 7 10:46:10 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[3011]: (EE) intel(0): failed to set mode: Numerical result out of range [34]
Sep 7 10:46:10 juho-ThinkPad-L460 gnome-session[3027]: Window manager warning: Configuring CRTC 63 with mode 226 (3840 x 2160 @ 59,996624) at position 0, 0 and transform 0 failed
Sep 7 10:46:10 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[3011]: (II) intel(0): switch to mode [email protected] on eDP1 using pipe 1, position (1920, 2160), rotation normal, reflection none
编辑：这是在displays-config中尝试4K并按下恢复后的完整journalctl输出。
syys 13 10:05:43 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[2928]: (II) intel(0): resizing framebuffer to 5760x2160
syys 13 10:05:44 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[2928]: (II) intel(0): switch to mode [email protected] on eDP1 using pipe 1, position (0, 0), rotation normal, reflection none
syys 13 10:05:45 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[2928]: (II) intel(0): switch to mode [email protected] on DP1 using pipe 0, position (1920, 0), rotation normal, reflection none
syys 13 10:05:45 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[2928]: (EE) intel(0): failed to set mode: Numerical result out of range [34]
syys 13 10:05:45 juho-ThinkPad-L460 gnome-session[2944]: Window manager warning: Configuring CRTC 63 with mode 226 (3840 x 2160 @ 59,996624) at position 1920, 0 and transform 0 failed
syys 13 10:05:51 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[2928]: (II) intel(0): resizing framebuffer to 4480x1440
syys 13 10:05:51 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[2928]: (II) intel(0): switch to mode [email protected] on eDP1 using pipe 0, position (0, 0), rotation normal, reflection none
syys 13 10:05:52 juho-ThinkPad-L460 kernel: ------------[ cut here ]------------
syys 13 10:05:52 juho-ThinkPad-L460 kernel: WARNING: CPU: 2 PID: 2930 at /home/kernel/COD/linux/drivers/gpu/drm/i915/intel_pm.c:3597 skl_update_other_pipe_wm+0x1de/0x1f0 [i915]()
syys 13 10:05:52 juho-ThinkPad-L460 kernel: WARN_ON(!wm_changed)
syys 13 10:05:52 juho-ThinkPad-L460 kernel: Modules linked in:
syys 13 10:05:52 juho-ThinkPad-L460 kernel: snd_seq_dummy rfcomm bnep snd_hda_codec_hdmi intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp snd_hda_codec_realtek snd_hda_codec_generic kvm arc4 binfmt_mis
syys 13 10:05:52 juho-ThinkPad-L460 kernel: mei snd_seq_device snd_timer snd soundcore mac_hid tpm_crb parport_pc ppdev lp parport autofs4 hid_generic usbhid hid rtsx_pci_sdmmc i915 e1000e ptp pps_core psmouse
syys 13 10:05:52 juho-ThinkPad-L460 kernel: CPU: 2 PID: 2930 Comm: Xorg Tainted: G W 4.4.8-040408-generic #201604200335
syys 13 10:05:52 juho-ThinkPad-L460 kernel: Hardware name: LENOVO 20FU002DMS/20FU002DMS, BIOS R08ET42W (1.16 ) 06/17/2016
syys 13 10:05:52 juho-ThinkPad-L460 kernel: 0000000000000286 00000000592b92cf ffff88030df67810 ffffffff813cee93
syys 13 10:05:52 juho-ThinkPad-L460 kernel: ffff88030df67858 ffffffffc0273c70 ffff88030df67848 ffffffff8107fe12
syys 13 10:05:52 juho-ThinkPad-L460 kernel: ffff88030df6797c ffff88003541e000 ffff88003541f000 0000000000000000
syys 13 10:05:52 juho-ThinkPad-L460 kernel: Call Trace:
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffff813cee93>] dump_stack+0x63/0x90
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffff8107fe12>] warn_slowpath_common+0x82/0xc0
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffff8107feac>] warn_slowpath_fmt+0x5c/0x80
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffffc01add9e>] skl_update_other_pipe_wm+0x1de/0x1f0 [i915]
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffffc01ae002>] skl_update_wm+0x252/0x7d0 [i915]
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffffc01f6ee4>] ? gen9_read32+0x124/0x2f0 [i915]
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffffc01b266e>] intel_update_watermarks+0x1e/0x30 [i915]
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffffc0217b77>] intel_atomic_commit+0x427/0x6f0 [i915]
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffffc007bb17>] drm_atomic_commit+0x37/0x60 [drm]
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffffc00ee5a6>] drm_atomic_helper_set_config+0x76/0xb0 [drm_kms_helper]
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffffc006ad22>] drm_mode_set_config_internal+0x62/0x100 [drm]
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffffc006f242>] drm_mode_setcrtc+0x3d2/0x4f0 [drm]
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffffc0060722>] drm_ioctl+0x152/0x540 [drm]
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffffc006ee70>] ? drm_mode_setplane+0x1b0/0x1b0 [drm]
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffff8121d108>] do_vfs_ioctl+0x298/0x480
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffff8108ceb1>] ? __set_task_blocked+0x41/0xa0
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffff8108f846>] ? __set_current_blocked+0x36/0x60
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffff8121d369>] SyS_ioctl+0x79/0x90
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffff8108fafe>] ? SyS_rt_sigprocmask+0x8e/0xc0
syys 13 10:05:52 juho-ThinkPad-L460 kernel: [<ffffffff81806276>] entry_SYSCALL_64_fastpath+0x16/0x75
syys 13 10:05:52 juho-ThinkPad-L460 kernel: ---[ end trace 972d78447654bc07 ]---
syys 13 10:05:52 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[2928]: (II) intel(0): switch to mode [email protected] on DP1 using pipe 1, position (1920, 0), rotation normal, reflection none
syys 13 10:05:53 juho-ThinkPad-L460 kernel: snd_hda_codec_hdmi hdaudioC0D2: HDMI: ELD buf size is 0, force 128
syys 13 10:05:53 juho-ThinkPad-L460 kernel: snd_hda_codec_hdmi hdaudioC0D2: HDMI: invalid ELD data byte 0
syys 13 10:05:53 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[2928]: (II) intel(0): resizing framebuffer to 1920x1080
syys 13 10:05:53 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[2928]: (II) intel(0): resizing framebuffer to 4480x1440
syys 13 10:05:53 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[2928]: (II) intel(0): switch to mode [email protected] on DP1 using pipe 0, position (1920, 0), rotation normal, reflection none
syys 13 10:05:53 juho-ThinkPad-L460 wpa_supplicant[2706]: wlp3s0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
syys 13 10:05:53 juho-ThinkPad-L460 /usr/lib/gdm3/gdm-x-session[2928]: (II) intel(0): switch to mode [email protected] on eDP1 using pipe 1, position (0, 0), rotation normal, reflection none
答案1
看起来您已经成为有问题的 i915 驱动程序的又一个受害者。
Fedora 错误报告中列出了许多可供尝试的选项 https://bugzilla.redhat.com/show_bug.cgi?id=1188772
最主要的是尝试改变加速方法，看看哪种方法最适合您的设置。
将其添加到您的 /etc/X11/xorg.conf.d/20-intel.conf 并通过取消注释其中一种来尝试每种不同的加速方法。
Section "Device"
Identifier "Intel Graphics"
Driver "intel"
# Option "AccelMethod" "sna"
# Option "AccelMethod" "uxa"
# Option "AccelMethod" "glamor"
Option "TearFree" "true"
EndSection
还有许多启动选项可能会有所帮助，要获取 i915 启动选项列表，请运行以下命令
modinfo i915 | grep '^parm:'
答案2
您可能需要检查显示器上是否启用了 DisplayPort 1.2。某些 UHD 显示器允许使用 OSD 选择 DisplayPort 版本。如果您的显示器默认为 1.1，则将其更改为 1.2 可能会有所帮助。