Hi,
Commit dc22ee6 introduces regression on my laptop HP EliteBook 8440p. I see nothing on the panel after mode setting. Reverting the commit fixes the issue.
$ sudo lspci -vv -xxxx -s 00:02.0 00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 02) (prog-if 00 [VGA controller]) Subsystem: Hewlett-Packard Company Device 172a 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 43 Region 0: Memory at d0000000 (64-bit, non-prefetchable) [size=4M] Region 2: Memory at c0000000 (64-bit, prefetchable) [size=256M] Region 4: I/O ports at 5058 [size=8] Expansion ROM at <unassigned> [disabled] Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit- Address: fee0f00c Data: 4179 Capabilities: [d0] Power Management version 2 Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Capabilities: [a4] PCI Advanced Features AFCap: TP+ FLR+ AFCtrl: FLR- AFStatus: TP- Kernel driver in use: i915 00: 86 80 46 00 07 04 90 00 02 00 00 03 00 00 00 00 10: 04 00 00 d0 00 00 00 00 0c 00 00 c0 00 00 00 00 20: 59 50 00 00 00 00 00 00 00 00 00 00 3c 10 2a 17 30: 00 00 00 00 90 00 00 00 00 00 00 00 0a 01 00 00 40: 09 00 0c 01 26 61 21 00 88 00 40 00 0f 17 17 17 50: 00 00 50 0b 09 00 00 00 00 00 00 00 00 00 00 be 60: 00 00 02 02 00 00 00 00 00 00 00 00 00 00 00 00 70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 90: 05 d0 01 00 0c f0 e0 fe 79 41 00 00 00 00 00 00 a0: 11 11 11 00 13 00 06 03 00 00 14 60 25 04 3a 30 b0: 00 00 00 00 00 00 00 00 00 02 00 00 00 00 00 00 c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 d0: 01 a4 22 00 00 00 00 00 00 00 00 00 00 01 02 00 e0: 00 00 00 00 01 00 00 00 00 80 00 00 00 00 00 00 f0: 00 00 00 00 00 00 00 00 ab 0f 18 00 18 d0 6f bb