插入 VGA 显示器后，登录 cinnamon 后出现带光标的黑屏

Question

我在安装 Ubuntu 16.04.1 LTS + Cinnamon 和 Linux Mint 18.1 + Cinnamon 时遇到问题：插入外部 VGA 显示器时登录后出现黑屏。这些是事实：

• 有时我打开电脑，用我的密码登录，然后黑屏。
• 发生这种情况时，光标始终可见。
• 在这些情况下，我仍然可以按 Ctrl+Alt+F1（虽然大约需要 30 秒），杀死 lightdm 或 mdm 并重试 - 在这一步之后我可能会成功，也可能不会成功。
• 发生这种情况时，Ctrl-Alt-Backspace 会重新启动 X（尽管大约需要 30 秒），简要显示墙纸并将我带到登录屏幕。
• 当我从运行级别 3 开始时，我仍然出现黑屏并且没有机会登录。
• 发生这种情况时，Ctrl-Alt-Del 会重新启动系统并显示启动画面。
• 在软件渲染模式下登录时，我可以毫无问题地登录。
• 在恢复模式下启动然后正常启动时，我可以毫无问题地登录，但是 a) 在软件渲染模式下和 b) 没有外部 VGA 显示器。
• 总是最终工作的一件事是在计算机上执行硬关机（按住电源按钮），然后我通常可以正常登录。
• 在 Ubuntu 上使用 Unity 不会发生这些问题。
• 在没有 VGA 屏幕的情况下启动时，一切正常。
• 登录后插VGA屏，画面卡死。
• 使用商业英特尔驱动程序不会解决问题。
• 使用“镜像”不起作用。
• 按照此错误报告中的建议更改布局不起作用。
• 按照此线程中的建议禁用桌面图标不起作用。

有没有系统的方法来调试这个问题并诊断问题？谁能指出我需要关注哪些重要信息来调试这个问题？X 日志，禁用屏幕保护程序，也许还有其他事情？

jlcano@jlcano ~ $ lsb_release -a
No LSB modules are available.
Distributor ID: LinuxMint
Description:    Linux Mint 18.1 Serena
Release:    18.1
Codename:   serena
jlcano@jlcano ~ $ uname -a
Linux jlcano 4.4.0-59-generic #80-Ubuntu SMP Fri Jan 6 17:47:47 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
jlcano@jlcano ~ $ inxi -Fx
System:    Host: jlcano Kernel: 4.4.0-57-generic x86_64 (64 bit gcc: 5.4.0)
           Desktop: Cinnamon 3.2.7 (Gtk 3.18.9-1ubuntu3.1)
           Distro: Linux Mint 18.1 Serena
Machine:   System: TOSHIBA product: Satellite Pro A50-C v: PS56AE-07S013CE
           Mobo: TOSHIBA model: Satellite Pro A50-C v: Version A0
           Bios: TOSHIBA v: Version 6.10 date: 07/15/2015
CPU:       Dual core Intel Core i7-5500U (-HT-MCP-) cache: 4096 KB
           flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 9577
           clock speeds: max: 3000 MHz 1: 2899 MHz 2: 2899 MHz 3: 2899 MHz
           4: 2899 MHz
Graphics:  Card: Intel Broadwell-U Integrated Graphics bus-ID: 00:02.0
           Display Server: X.Org 1.18.4 drivers: intel (unloaded: fbdev,vesa)
           Resolution: 1366x768@60.00hz, 1920x1080@60.00hz
           GLX Renderer: Gallium 0.4 on llvmpipe (LLVM 3.8, 256 bits)
           GLX Version: 3.0 Mesa 11.2.0 Direct Rendering: Yes
Audio:     Card-1 Intel Wildcat Point-LP High Definition Audio Controller
           driver: snd_hda_intel bus-ID: 00:1b.0
           Card-2 Intel Broadwell-U Audio Controller
           driver: snd_hda_intel bus-ID: 00:03.0
           Sound: Advanced Linux Sound Architecture v: k4.4.0-57-generic
Network:   Card-1: Intel Ethernet Connection (3) I218-V
           driver: e1000e v: 3.2.6-k port: 3080 bus-ID: 00:19.0
           IF: enp0s25 state: up speed: 1000 Mbps duplex: full
           mac: b8:6b:23:10:be:c6
           Card-2: Intel Wireless 7265 driver: iwlwifi bus-ID: 02:00.0
           IF: wlp2s0 state: down mac: 10:02:b5:1c:dc:2a
Drives:    HDD Total Size: 1000.2GB (2.2% used)
           ID-1: /dev/sda model: TOSHIBA_MQ01ABD1 size: 1000.2GB
Partition: ID-1: / size: 622G used: 14G (3%) fs: ext4 dev: /dev/sda5
           ID-2: swap-1 size: 8.50GB used: 0.00GB (0%) fs: swap dev: /dev/sda6
RAID:      No RAID devices: /proc/mdstat, md_mod kernel module present
Sensors:   System Temperatures: cpu: 75.0C mobo: N/A
           Fan Speeds (in rpm): cpu: N/A
Info:      Processes: 188 Uptime: 26 min Memory: 1103.9/7892.8MB
           Init: systemd runlevel: 5 Gcc sys: 5.4.0
           Client: Shell (bash 4.3.461) inxi: 2.2.35 
jlcano@jlcano ~ $ lspci -nn
00:00.0 Host bridge [0600]: Intel Corporation Broadwell-U Host Bridge -OPI [8086:1604] (rev 09)
00:02.0 VGA compatible controller [0300]: Intel Corporation Broadwell-U Integrated Graphics [8086:1616] (rev 09)
00:03.0 Audio device [0403]: Intel Corporation Broadwell-U Audio Controller [8086:160c] (rev 09)
00:14.0 USB controller [0c03]: Intel Corporation Wildcat Point-LP USB xHCI Controller [8086:9cb1] (rev 03)
00:16.0 Communication controller [0780]: Intel Corporation Wildcat Point-LP MEI Controller #1 [8086:9cba] (rev 03)
00:19.0 Ethernet controller [0200]: Intel Corporation Ethernet Connection (3) I218-V [8086:15a3] (rev 03)
00:1b.0 Audio device [0403]: Intel Corporation Wildcat Point-LP High Definition Audio Controller [8086:9ca0] (rev 03)
00:1c.0 PCI bridge [0604]: Intel Corporation Wildcat Point-LP PCI Express Root Port #6 [8086:9c9a] (rev e3)
00:1c.2 PCI bridge [0604]: Intel Corporation Wildcat Point-LP PCI Express Root Port #3 [8086:9c94] (rev e3)
00:1d.0 USB controller [0c03]: Intel Corporation Wildcat Point-LP USB EHCI Controller [8086:9ca6] (rev 03)
00:1f.0 ISA bridge [0601]: Intel Corporation Wildcat Point-LP LPC Controller [8086:9cc3] (rev 03)
00:1f.2 SATA controller [0106]: Intel Corporation Wildcat Point-LP SATA Controller [AHCI Mode] [8086:9c83] (rev 03)
02:00.0 Network controller [0280]: Intel Corporation Wireless 7265 [8086:095a] (rev 61)
jlcano@jlcano ~ $ cat .xsession-errors 
initctl: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused
/etc/mdm/Xsession: Beginning session setup...
localuser:jlcano being added to access control list
SSH_AUTH_SOCK=/run/user/1000/keyring/ssh
SSH_AUTH_SOCK=/run/user/1000/keyring/ssh
SSH_AUTH_SOCK=/run/user/1000/keyring/ssh
Window manager warning: Software rendering detected: Gallium 0.4 on llvmpipe (LLVM 3.8, 256 bits)
Unhandled exception in thread started by 
sys.excepthook is missing
lost sys.stderr
Cjs-Message: JS LOG: About to start Cinnamon
Cjs-Message: JS LOG: ACTIVATING SOFTWARE RENDERING
St-Message: cogl npot texture sizes SUPPORTED
Cjs-Message: JS LOG: Cinnamon started at Tue Jan 10 2017 09:46:23 GMT+0100 (CET)
Cjs-Message: JS LOG: network applet: Cannot find connection for active (or connection cannot be read)
openGL version 3.3 detected (GL3 Cogl Driver)
MetaSyncRing disabled: couldn't find required GL extensions, or the minimum safe openGL version was not met
Cjs-Message: JS LOG: Invalid network device type, is 14
Cjs-Message: JS LOG: network applet: Found connection for active
Cjs-Message: JS LOG: Removing an access point that was never added
mintUpdate: no process found
Window manager warning: Log level 8: meta_window_move_resize: assertion '!window->override_redirect' failed
Window manager warning: Log level 8: meta_window_move_resize: assertion '!window->override_redirect' failed
Window manager warning: Log level 8: meta_window_move_resize: assertion '!window->override_redirect' failed
Window manager warning: Log level 8: meta_window_move_resize: assertion '!window->override_redirect' failed
Window manager warning: Log level 8: meta_window_move_resize: assertion '!window->override_redirect' failed
Window manager warning: Log level 8: meta_window_move_resize: assertion '!window->override_redirect' failed
Window manager warning: Log level 8: meta_window_move_resize: assertion '!window->override_redirect' failed
Window manager warning: Log level 8: meta_window_move_resize: assertion '!window->override_redirect' failed
Window manager warning: Log level 8: meta_window_move_resize: assertion '!window->override_redirect' failed
Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.
jlcano@jlcano ~ $ sudo lshw -c video
[sudo] password for jlcano: 
  *-display               
       description: VGA compatible controller
       product: Broadwell-U Integrated Graphics
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 09
       width: 64 bits
       clock: 33MHz
       capabilities: msi pm vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:45 memory:f0000000-f0ffffff memory:e0000000-efffffff ioport:3000(size=64)

sensors使用一整天后编辑输出：

jlcano@jlcano ~ $ sensors
acpitz-virtual-0
Adapter: Virtual device
temp1:        +85.0°C  (crit = +107.0°C)

coretemp-isa-0000
Adapter: ISA adapter
Physical id 0:  +49.0°C  (high = +105.0°C, crit = +105.0°C)
Core 0:         +49.0°C  (high = +105.0°C, crit = +105.0°C)
Core 1:         +49.0°C  (high = +105.0°C, crit = +105.0°C)

编辑从 OP 中删除的答案“仅设置外部显示器并禁用笔记本电脑屏幕确实有效。”

Answer 1

根据您的传感器输出：

Sensors:   System Temperatures: cpu: 75.0C mobo: N/A
           Fan Speeds (in rpm): cpu: N/A

如果此信息准确，我会说您的 CPU 过热并降频以试图保护自身，从而导致您在访问终端和重新启动 X 时遇到延迟。据我所知，Broadwell -U 系列并非旨在在这些温度下运行，可能会因过热而损坏。根本原因可能是风扇不旋转导致冷却不足。

如果没有相关硬件，我无法确定您提供的传感器输出是否准确。然而，如果是这样，那就需要立即关注并应立即解决。

由于 Broadwell-U 系列具有集成显卡，因此过热导致故障可能是您遇到图形问题的原因。