Dois monitores externos no Dell XPS 9350 (modelo 2016)

Question

No Dell XPS 9350 (modelo 2016), você precisa usar a porta USB-C, se quiser aproveitar um monitor externo. Um dos adaptadores USB-C é o Adaptador Dell - USB-C para HDMI / VGA / Ethernet / USB 3.0 (DA200) .

Quando eu conecto o adaptador na máquina eu tenho

$ dmesg
[426949.056524] hub 4-0:1.0: USB hub found
[426949.056543] hub 4-0:1.0: 2 ports detected
[426949.417197] usb 3-1: new high-speed USB device number 2 using xhci_hcd
[426949.599546] hub 3-1:1.0: USB hub found
[426949.600098] hub 3-1:1.0: 4 ports detected
[426949.695244] usb 4-1: new SuperSpeed USB device number 2 using xhci_hcd
[426949.712836] hub 4-1:1.0: USB hub found
[426949.713151] hub 4-1:1.0: 4 ports detected
[426949.878311] usb 3-1.3: new full-speed USB device number 3 using xhci_hcd
[426949.960668] usb 3-1.3: config 1 has no interfaces?
[426950.025168] usb 4-1.4: new SuperSpeed USB device number 3 using xhci_hcd
[426950.115300] usb 4-1.4: reset SuperSpeed USB device number 3 using xhci_hcd
[426950.156378] r8152 4-1.4:1.0 eth0: v1.08.3
[426951.795777] r8152 4-1.4:1.0 enp57s0u1u4: renamed from eth0
$ xrandr
Screen 0: minimum 8 x 8, current 3200 x 1800, maximum 32767 x 32767
eDP1 connected primary 3200x1800+0+0 (normal left inverted right x axis y axis) 290mm x 170mm
   3200x1800     59.98*+  47.99  
   2880x1620     60.00  
   2560x1440     60.00  
   2048x1536     60.00  
   1920x1440     60.00  
   1856x1392     60.01  
   1792x1344     60.01  
   2048x1152     60.00  
   1920x1080     60.00  
   1600x1200     60.00  
   1400x1050     59.98  
   1600x900      60.00  
   1280x1024     60.02  
   1280x960      60.00  
   1368x768      60.00  
   1280x720      60.00  
   1024x768      60.00  
   1024x576      60.00  
   960x540       60.00  
   800x600       60.32    56.25  
   864x486       60.00  
   640x480       59.94  
   720x405       60.00  
   640x360       60.00  
DP1 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

Eu posso conectar um monitor externo usando a porta HDMI e recebo

$ xrandr
Screen 0: minimum 8 x 8, current 3200 x 1800, maximum 32767 x 32767
eDP1 connected primary 3200x1800+0+0 (normal left inverted right x axis y axis) 290mm x 170mm
   3200x1800     59.98*+  47.99  
   2880x1620     60.00  
   2560x1440     60.00  
   2048x1536     60.00  
   1920x1440     60.00  
   1856x1392     60.01  
   1792x1344     60.01  
   2048x1152     60.00  
   1920x1080     60.00  
   1600x1200     60.00  
   1400x1050     59.98  
   1600x900      60.00  
   1280x1024     60.02  
   1280x960      60.00  
   1368x768      60.00  
   1280x720      60.00  
   1024x768      60.00  
   1024x576      60.00  
   960x540       60.00  
   800x600       60.32    56.25  
   864x486       60.00  
   640x480       59.94  
   720x405       60.00  
   640x360       60.00  
DP1 connected (normal left inverted right x axis y axis)
   1920x1080     60.00 +  50.00    59.94  
   1920x1080i    60.00    50.00    59.94  
   1280x1024     75.02    60.02  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    60.00  
   800x600       75.00    60.32  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    60.00    59.94  
   720x400       70.08  
DP2 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

Exceto pelo fato de o monitor externo não funcionar com altas resoluções , tudo funciona conforme o esperado.

E eu posso conectar outro monitor externo usando a porta VGA. Agora vou pegar

$ xrandr
Screen 0: minimum 8 x 8, current 3200 x 1800, maximum 32767 x 32767
eDP1 connected primary 3200x1800+0+0 (normal left inverted right x axis y axis) 290mm x 170mm
   3200x1800     59.98*+  47.99  
   2880x1620     60.00  
   2560x1440     60.00  
   2048x1536     60.00  
   1920x1440     60.00  
   1856x1392     60.01  
   1792x1344     60.01  
   2048x1152     60.00  
   1920x1080     60.00  
   1600x1200     60.00  
   1400x1050     59.98  
   1600x900      60.00  
   1280x1024     60.02  
   1280x960      60.00  
   1368x768      60.00  
   1280x720      60.00  
   1024x768      60.00  
   1024x576      60.00  
   960x540       60.00  
   800x600       60.32    56.25  
   864x486       60.00  
   640x480       59.94  
   720x405       60.00  
   640x360       60.00  
DP1 connected (normal left inverted right x axis y axis)
   1680x1050     59.95 +
   1280x1024     75.02    60.02  
   1152x864      75.00  
   1024x768      75.03    60.00  
   800x600       75.00    60.32  
   640x480       75.00    59.94  
   720x400       70.08  
DP2 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

O monitor conectado na porta VGA funciona mas o monitor conectado na porta HDMI não funciona mais.

Da saída xrandr , podemos ver que as portas HDMI e VGA estão usando o fluxo xrandr DP1. Por que ? Posso alterar qualquer configuração para poder usar as duas portas ao mesmo tempo?

Nota: Como mostra a figura abaixo, eu tive que cortar um dos parafusos do adaptador VGA.

Configuração da máquina

$ lspci
00:00.0 Host bridge: Intel Corporation Skylake Host Bridge/DRAM Registers (rev 09)
00:02.0 VGA compatible controller: Intel Corporation Skylake Integrated Graphics (rev 0a)
00:04.0 Signal processing controller: Intel Corporation Skylake Processor Thermal Subsystem (rev 09)
00:14.0 USB controller: Intel Corporation Sunrise Point-LP USB 3.0 xHCI Controller (rev 21)
00:14.2 Signal processing controller: Intel Corporation Sunrise Point-LP Thermal subsystem (rev 21)
00:15.0 Signal processing controller: Intel Corporation Sunrise Point-LP Serial IO I2C Controller #0 (rev 21)
00:15.1 Signal processing controller: Intel Corporation Sunrise Point-LP Serial IO I2C Controller #1 (rev 21)
00:16.0 Communication controller: Intel Corporation Sunrise Point-LP CSME HECI #1 (rev 21)
00:17.0 RAID bus controller: Intel Corporation 82801 Mobile SATA Controller [RAID mode] (rev 21)
00:1c.0 PCI bridge: Intel Corporation Device 9d10 (rev f1)
00:1c.4 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #5 (rev f1)
00:1c.5 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #6 (rev f1)
00:1d.0 PCI bridge: Intel Corporation Device 9d18 (rev f1)
00:1f.0 ISA bridge: Intel Corporation Sunrise Point-LP LPC Controller (rev 21)
00:1f.2 Memory controller: Intel Corporation Sunrise Point-LP PMC (rev 21)
00:1f.3 Audio device: Intel Corporation Sunrise Point-LP HD Audio (rev 21)
00:1f.4 SMBus: Intel Corporation Sunrise Point-LP SMBus (rev 21)
01:00.0 PCI bridge: Intel Corporation DSL5110 Thunderbolt Bridge [Falcon Ridge LP 2014]
02:00.0 PCI bridge: Intel Corporation DSL5110 Thunderbolt Bridge [Falcon Ridge LP 2014]
02:01.0 PCI bridge: Intel Corporation DSL5110 Thunderbolt Bridge [Falcon Ridge LP 2014]
02:02.0 PCI bridge: Intel Corporation DSL5110 Thunderbolt Bridge [Falcon Ridge LP 2014]
39:00.0 USB controller: Intel Corporation Device 15b5
3a:00.0 Network controller: Broadcom Corporation BCM4350 802.11ac Wireless Network Adapter (rev 08)
3b:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS525A PCI Express Card Reader (rev 01)
3c:00.0 Non-Volatile memory controller: Toshiba America Info Systems Device 010f (rev 01)

Configuração do sistema

Kernel 4.6.2