LG Displays are being reported as "disconnected" when they are powered off (currently connected through DVI to mini-displayport adapter)
Only seeing this with LG displays (have tested NEC and Samsung *limited model types for each manufacturer*). With the LG display connected to the graphics card and powered off the system is reporting the DisplayPort as disconnected. In any kernel <= 4.4.0-31 the system would report the DisplayPort as connected even if the LG display was off.
Kernel tested on Linux version 4.4.0-66-generic (buildd@lgw01-28) (gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.4) ) #87-Ubuntu
Most recent kernel without the bug: Linux version 4.4.0-31-generic (buildd@lgw01-16) (gcc version 5.3.1 20160413 (Ubuntu 5.3.1-14ubuntu2.1) ) #50-Ubuntu
"cat /sys/class/drm/card1-DP-1/status" will show the status as disconnected if the LG display is powered off
Environment Ubuntu 16.04 Graphics Card: Cape Verde PRO [Radeon HD 7750/8740 / R7 250E] Radeon Graphics Drivers Kernel: 4.4.0-66
Processor processor : 0-3 vendor_id : AuthenticAMD cpu family : 21 model : 48 model name : AMD A8-7600 Radeon R7, 10 Compute Cores 4C+6G stepping : 1 microcode : 0x6003106 cpu MHz : 1400.000 cache size : 2048 KB physical id : 0 siblings : 4 core id : 0 cpu cores : 2 apicid : 16 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc extd_apicid aperfmperf eagerfpu pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 popcnt aes xsave avx f16c lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs xop skinit wdt lwp fma4 tce nodeid_msr tbm topoext perfctr_core perfctr_nb bpext cpb hw_pstate vmmcall fsgsbase bmi1 xsaveopt arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold bugs : fxsave_leak sysret_ss_attrs bogomips : 6188.48 TLB size : 1536 4K pages clflush size : 64 cache_alignment : 64 address sizes : 48 bits physical, 48 bits virtual power management: ts ttp tm 100mhzsteps hwpstate cpb eff_freq_ro [13]
Loaded driver and hardware information cat /proc/ioports: 0000-03af : PCI Bus 0000:00 0000-001f : dma1 0020-0021 : pic1 0040-0043 : timer0 0050-0053 : timer1 0060-0060 : keyboard 0061-0061 : PNP0800:00 0064-0064 : keyboard 0070-0071 : rtc0 0080-008f : dma page reg 00a0-00a1 : pic2 00c0-00df : dma2 00f0-00ff : PNP0C04:00 00f0-00ff : fpu 03b0-03df : PCI Bus 0000:00 03c0-03df : vesafb 03e0-0cf7 : PCI Bus 0000:00 03f8-03ff : serial 040b-040b : pnp 00:08 04d0-04d1 : pnp 00:07 04d0-04d1 : pnp 00:08 04d6-04d6 : pnp 00:08 0800-0803 : ACPI PM1a_EVT_BLK 0804-0805 : ACPI PM1a_CNT_BLK 0808-080b : ACPI PM_TMR 0810-0815 : ACPI CPU throttle 0820-0827 : ACPI GPE0_BLK 0900-090f : pnp 00:08 0910-091f : pnp 00:08 0a00-0a0f : pnp 00:03 0a00-0a07 : f71882fg 0a10-0a1f : pnp 00:03 0b00-0b07 : piix4_smbus 0b20-0b3f : pnp 00:08 0b20-0b27 : piix4_smbus 0c00-0c01 : pnp 00:08 0c14-0c14 : pnp 00:08 0c50-0c51 : pnp 00:08 0c52-0c52 : pnp 00:08 0c6c-0c6c : pnp 00:08 0c6f-0c6f : pnp 00:08 0cd0-0cd1 : pnp 00:08 0cd2-0cd3 : pnp 00:08 0cd4-0cd5 : pnp 00:08 0cd6-0cd7 : pnp 00:08 0cd8-0cdf : pnp 00:08 0cf8-0cff : PCI conf1 0d00-ffff : PCI Bus 0000:00 d000-dfff : PCI Bus 0000:02 d000-d0ff : 0000:02:00.0 d000-d0ff : r8169 e000-efff : PCI Bus 0000:01 e000-e0ff : 0000:01:00.0 f000-f0ff : 0000:00:01.0 f100-f10f : 0000:00:11.0 f100-f10f : ahci f110-f113 : 0000:00:11.0 f110-f113 : ahci f120-f127 : 0000:00:11.0 f120-f127 : ahci f130-f133 : 0000:00:11.0 f130-f133 : ahci f140-f147 : 0000:00:11.0 f140-f147 : ahci fe00-fefe : pnp 00:08
PCI Information 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Cape Verde PRO [Radeon HD 7750/8740 / R7 250E] (prog-if 00 [VGA controller]) Subsystem: Hightech Information System Ltd. Cape Verde PRO [Radeon HD 7750/8740 / R7 250E] 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, Cache Line Size: 64 bytes Interrupt: pin A routed to IRQ 48 Region 0: Memory at c0000000 (64-bit, prefetchable) [size=256M] Region 2: Memory at fea00000 (64-bit, non-prefetchable) [size=256K] Region 4: I/O ports at e000 [size=256] Expansion ROM at fea40000 [disabled] [size=128K] Capabilities: [48] Vendor Specific Information: Len=08 <?> Capabilities: [50] Power Management version 3 Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA PME(D0-,D1+,D2+,D3hot+,D3cold-) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Capabilities: [58] Express (v2) Legacy Endpoint, MSI 00 DevCap: MaxPayload 256 bytes, PhantFunc 0, Latency L0s <4us, L1 unlimited ExtTag+ AttnBtn- AttnInd- PwrInd- RBE+ FLReset- DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop+ MaxPayload 256 bytes, MaxReadReq 512 bytes DevSta: CorrErr+ UncorrErr- FatalErr- UnsuppReq+ AuxPwr- TransPend- LnkCap: Port #0, Speed 8GT/s, Width x16, ASPM L0s L1, Exit Latency L0s <64ns, L1 <1us ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp+ LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- CommClk+ ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed 8GT/s, Width x16, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt- DevCap2: Completion Timeout: Not Supported, TimeoutDis-, LTR-, OBFF Not Supported DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-, LTR-, OBFF Disabled LnkCtl2: Target Link Speed: 8GT/s, EnterCompliance- SpeedDis- Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS- Compliance De-emphasis: -6dB LnkSta2: Current De-emphasis Level: -6dB, EqualizationComplete+, EqualizationPhase1+ EqualizationPhase2+, EqualizationPhase3+, LinkEqualizationRequest- Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+ Address: 00000000fee00000 Data: 0000 Capabilities: [100 v1] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?> Capabilities: [150 v2] Advanced Error Reporting UESta: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol- UEMsk: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol- UESvrt: DLP+ SDES+ TLP- FCP+ CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol- CESta: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr+ CEMsk: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr+ AERCap: First Error Pointer: 00, GenCap+ CGenEn- ChkCap+ ChkEn- Capabilities: [200 v1] #15 Capabilities: [270 v1] #19 Kernel driver in use: radeon Kernel modules: radeon
Tom Reddish Software Engineer MediaVue Systems Skype: t.reddish Tel: +1 781.926.0676 w applewebdata://C141DA2B-2739-4B75-A3F2-C9B0A1593AB1/www.mediavuesystems.comww.mediavuesystems.com applewebdata://C141DA2B-2739-4B75-A3F2-C9B0A1593AB1/www.mediavuesystems.com