Meu laptop é um Acer Aspire M e eu costumava conectar um segundo monitor via HDMI regularmente. Há cerca de um mês, simplesmente parou de funcionar. Eu realmente não sei nada que possa fazer, então qualquer ajuda seria muito apreciada.
Hoje percebi que ao conectar o segundo monitor, apareciam as seguintes mensagens no TTY1, que também encontrei em kern.log
Jul 25 17:38:44 CNPq-Universal-2013 kernel: [122775.342394] ACPI: \_SB_.PCI0: Bus check notify on hotplug_event_root
Jul 25 17:38:44 CNPq-Universal-2013 kernel: [122775.800703] [drm:intel_dp_start_link_train] *ERROR* too many voltage retries, give up
Jul 25 18:41:15 CNPq-Universal-2013 kernel: [126528.997425] ACPI: \_SB_.PCI0: Bus check notify on hotplug_event_root
Jul 25 18:41:16 CNPq-Universal-2013 kernel: [126529.453129] [drm:intel_dp_start_link_train] *ERROR* too many voltage retries, give up
Jul 25 19:24:42 CNPq-Universal-2013 kernel: [129136.555803] ACPI: \_SB_.PCI0: Bus check notify on hotplug_event_root
Jul 25 19:24:42 CNPq-Universal-2013 kernel: [129137.016462] [drm:intel_dp_start_link_train] *ERROR* too many voltage retries, give up
Jul 25 19:30:39 CNPq-Universal-2013 kernel: [129493.589703] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:30:39 CNPq-Universal-2013 kernel: [129493.711272] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:30:39 CNPq-Universal-2013 kernel: [129493.736376] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:30:39 CNPq-Universal-2013 kernel: [129493.736391] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:30:39 CNPq-Universal-2013 kernel: [129493.761667] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:32:06 CNPq-Universal-2013 kernel: [129580.669767] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:32:06 CNPq-Universal-2013 kernel: [129580.763589] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:32:06 CNPq-Universal-2013 kernel: [129580.788761] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:32:06 CNPq-Universal-2013 kernel: [129580.788778] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:32:06 CNPq-Universal-2013 kernel: [129580.814130] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:02 CNPq-Universal-2013 kernel: [129636.517006] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:02 CNPq-Universal-2013 kernel: [129636.541971] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:02 CNPq-Universal-2013 kernel: [129636.541981] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:11 CNPq-Universal-2013 kernel: [129646.293981] Watchdog[2574]: segfault at 0 ip 00007fea75b0eb88 sp 00007fea66d22720 error 6 in libcontent.so[7fea753aa000+fd7000]
Jul 25 19:33:15 CNPq-Universal-2013 kernel: [129650.199365] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:15 CNPq-Universal-2013 kernel: [129650.263559] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:15 CNPq-Universal-2013 kernel: [129650.288593] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:15 CNPq-Universal-2013 kernel: [129650.288688] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:16 CNPq-Universal-2013 kernel: [129650.515649] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:21 CNPq-Universal-2013 kernel: [129655.576538] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:25 CNPq-Universal-2013 kernel: [129659.687743] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:25 CNPq-Universal-2013 kernel: [129659.713246] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:25 CNPq-Universal-2013 kernel: [129659.713313] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:25 CNPq-Universal-2013 kernel: [129659.787798] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:34 CNPq-Universal-2013 kernel: [129668.757269] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:34 CNPq-Universal-2013 kernel: [129668.823856] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:34 CNPq-Universal-2013 kernel: [129668.848773] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:34 CNPq-Universal-2013 kernel: [129668.848824] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:33:34 CNPq-Universal-2013 kernel: [129669.076025] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 248
Jul 25 19:34:16 CNPq-Universal-2013 kernel: [129711.120207] Watchdog[10511]: segfault at 0 ip 00007fc2caa07b88 sp 00007fc2bbc1b720 error 6 in libcontent.so[7fc2ca2a3000+fd7000]
Vi outra pessoa postando esses detalhes, então postarei o mesmo se ajudar.
$ uname -a
Linux CNPq-Universal-2013 3.13.0-32-generic #57-Ubuntu SMP Tue Jul 15 03:51:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
$ cat /etc/*-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.1 LTS"
NAME="Ubuntu"
VERSION="14.04.1 LTS, Trusty Tahr"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 14.04.1 LTS"
VERSION_ID="14.04"
HOME_URL="http://www.ubuntu.com/"
SUPPORT_URL="http://help.ubuntu.com/"
BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"
$lspci -vv
00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09) (prog-if 00 [VGA controller])
Subsystem: Acer Incorporated [ALI] Device 0712
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0
Interrupt: pin A routed to IRQ 45
Region 0: Memory at c2000000 (64-bit, non-prefetchable) [size=4M]
Region 2: Memory at b0000000 (64-bit, prefetchable) [size=256M]
Region 4: I/O ports at 3000 [size=64]
Expansion ROM at <unassigned> [disabled]
Capabilities: <access denied>
Kernel driver in use: i915
$ lsmod |grep video
uvcvideo 80885 0
videobuf2_vmalloc 13216 1 uvcvideo
videobuf2_memops 13362 1 videobuf2_vmalloc
videobuf2_core 40664 1 uvcvideo
videodev 134688 2 uvcvideo,videobuf2_core
video 19476 2 i915,acer_wmi