So I know this is a kernel issue already. Kernel v3, no problems, but kernel v4 is when the issue started. The tl'dr is: How can I choose the display port on boot? More info:
The modeset line gets me what I need..which is to poweroff the screen after a timeout. The issue is that with that modeset the wrong display port is used...one that doesn't have a monitor attached so the main screen is completely blank. With no modeset specified I get a normal screen, but no dpms. I've looked high and low, but I've not found any kernel options to boot to change the display port. It's not running X windows. Thank you.
Code:
[ 10.996745] radeon 0000:02:00.0: firmware: direct-loading firmware radeon/RV770_uvd.bin
[ 10.996795] [drm] GART: num cpu pages 262144, num gpu pages 262144
[ 10.997981] [drm] enabling PCIE gen 2 link speeds, disable with radeon.pcie_gen2=0
[ 11.001968] [drm] PCIE GART of 1024M enabled (table at 0x0000000000258000).
[ 11.002004] radeon 0000:02:00.0: WB enabled
[ 11.002009] radeon 0000:02:00.0: fence driver on ring 0 use gpu addr 0x0000000020000c00 and cpu addr 0xffff8802355a2c00
[ 11.002015] radeon 0000:02:00.0: fence driver on ring 3 use gpu addr 0x0000000020000c0c and cpu addr 0xffff8802355a2c0c
[ 11.002498] radeon 0000:02:00.0: fence driver on ring 5 use gpu addr 0x0000000000056230 and cpu addr 0xffffc90001016230
[ 11.002505] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[ 11.002508] [drm] Driver supports precise vblank timestamp query.
[ 11.002512] radeon 0000:02:00.0: radeon: MSI limited to 32-bit
[ 11.002543] radeon 0000:02:00.0: radeon: using MSI.
[ 11.002570] [drm] radeon: irq initialized.
[ 11.048841] [drm] ring test on 0 succeeded in 1 usecs
[ 11.048850] [drm] ring test on 3 succeeded in 2 usecs
[ 11.099988] Adding 7812092k swap on /dev/sda3. Priority:-1 extents:1 across:7812092k FS
[ 11.223502] [drm] ring test on 5 succeeded in 1 usecs
[ 11.223513] [drm] UVD initialized successfully.
[ 11.223859] [drm] ib test on ring 0 succeeded in 0 usecs
[ 11.223877] [drm] ib test on ring 3 succeeded in 0 usecs
[ 11.430422] FAT-fs (sda1): utf8 is not a recommended IO charset for FAT filesystems, filesystem will be case sensitive!
[ 11.872125] [drm] ib test on ring 5 succeeded
[ 11.872601] [drm] radeon atom DIG backlight initialized
[ 11.872605] [drm] Radeon Display Connectors
[ 11.872608] [drm] Connector 0:
[ 11.872611] [drm] DP-1
[ 11.872614] [drm] HPD2
[ 11.872617] [drm] DDC: 0x7e60 0x7e60 0x7e64 0x7e64 0x7e68 0x7e68 0x7e6c 0x7e6c
[ 11.872622] [drm] Encoders:
[ 11.872625] [drm] DFP1: INTERNAL_UNIPHY
[ 11.872628] [drm] Connector 1:
[ 11.872631] [drm] DP-2
[ 11.872633] [drm] HPD3
[ 11.872636] [drm] DDC: 0x7e20 0x7e20 0x7e24 0x7e24 0x7e28 0x7e28 0x7e2c 0x7e2c
[ 11.872641] [drm] Encoders:
[ 11.872644] [drm] DFP2: INTERNAL_UNIPHY
[ 11.872647] [drm] Connector 2:
[ 11.872649] [drm] LVDS-1
[ 11.872652] [drm] Encoders:
[ 11.872655] [drm] LCD1: INTERNAL_KLDSCP_LVTMA
[ 11.872658] [drm] Connector 3:
[ 11.872661] [drm] VGA-1
[ 11.872664] [drm] DDC: 0x7e40 0x7e40 0x7e44 0x7e44 0x7e48 0x7e48 0x7e4c 0x7e4c
[ 11.872669] [drm] Encoders:
[ 11.872671] [drm] CRT1: INTERNAL_KLDSCP_DAC1
[ 12.260545] input: HDA Digital PCBeep as /devices/pci0000:00/0000:00:08.0/sound/card0/input9
[ 12.261317] input: HDA NVidia Mic as /devices/pci0000:00/0000:00:08.0/sound/card0/input10
[ 12.261675] input: HDA NVidia Line as /devices/pci0000:00/0000:00:08.0/sound/card0/input11
[ 12.261911] input: HDA NVidia Headphone as /devices/pci0000:00/0000:00:08.0/sound/card0/input12
[ 12.561492] [drm] fb mappable at 0xC0459000
[ 12.561499] [drm] vram apper at 0xC0000000
[ 12.561502] [drm] size 5947392
[ 12.561505] [drm] fb depth is 24
[ 12.561508] [drm] pitch is 5632
[ 12.561595] fbcon: radeondrmfb (fb0) is primary device
[ 12.640199] Console: switching to colour frame buffer device 175x65
[ 12.643081] radeon 0000:02:00.0: fb0: radeondrmfb frame buffer device
[ 12.660064] [drm] Initialized radeon 2.43.0 20080528 for 0000:02:00.0 on minor 0
02:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV770/M98L [Mobility Radeon HD 4850]
GRUB_CMDLINE_LINUX_DEFAULT="radeon.modeset=1"