i386 i915drmkms on 82915GM (eeepc 900)

[mlh%goathill.org@localhost (MLH)]

I recently installed 7.99.5 (GENERIC) Sat Feb 14 17:41:04 EST 2015
i386 on a usb drive connected to an ASUS EEEPC 900. I ran NetBSD
5/6 on it for the last 6 or so years.  I currently also have the
VGA output connected to an external monitor.

During startup, the LVDS display works fine until about the time
the startup messages reach "i915drmkms0". At this time, the external
monitor console display switches to a higher resolution and the
LVDS goes blank. I can start X on the external monitor but only at
low resolutions. I can't get the LVDS monitor to work after bootup.

$ xrandr
Screen 0: minimum 320 x 200, current 640 x 480, maximum 4096 x 4096
LVDS1 connected 640x480+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   640x480       72.81    75.00    59.94* 
VGA1 connected 640x480+0+0 (normal left inverted right x axis y axis) 518mm x 324mm
   1024x768      60.00  
   800x600       60.32    56.25  
   848x480       60.00  
   640x480       59.94* 
TV1 unknown connection (normal left inverted right x axis y axis)
   848x480       59.94 +
   640x480       59.94 +
   1024x768      59.94  
   800x600       59.94  


NetBSD 7.99.5 (GENERIC) #1: Sat Feb 14 17:41:04 EST 2015
        {}/src/sys/arch/i386/compile/GENERIC
total memory = 1015 MB
avail memory = 980 MB
timecounter: Timecounters tick every 10.000 msec
timecounter: Timecounter "i8254" frequency 1193182 Hz quality 100
ASUSTeK Computer INC. 900 (0802)
mainbus0 (root)
ACPI: RSDP 0x000FBE60 000014 (v00 ACPIAM)
ACPI: RSDT 0x3F780000 000034 (v01 A M I  OEMRSDT  07000807 MSFT 00000097)
ACPI: FACP 0x3F780200 000081 (v01 A M I  OEMFACP  07000807 MSFT 00000097)
ACPI: DSDT 0x3F780400 006105 (v01 A0979  A0979029 00000029 INTL 20060113)
ACPI: FACS 0x3F790000 000040
ACPI: APIC 0x3F780390 000068 (v01 A M I  OEMAPIC  07000807 MSFT 00000097)
ACPI: OEMB 0x3F790040 000046 (v01 A M I  AMI_OEM  07000807 MSFT 00000097)
ACPI: MCFG 0x3F786510 00003C (v01 A M I  OEMMCFG  07000807 MSFT 00000097)
ACPI: All ACPI Tables successfully acquired
cpu0 at mainbus0 apid 0
cpu0: Intel(R) Celeron(R) M processor          900MHz, id 0x6d8
ioapic0 at mainbus0 apid 1: pa 0xfec00000, version 0x20, 24 pins
acpi0 at mainbus0: Intel ACPICA 20140926
acpi0: X/RSDT: OemId <A M I ,OEMRSDT ,07000807>, AslId <MSFT,00000097>
acpi0: SCI interrupting at int 9
...
acpiec0 at acpi0 (EC0, PNP0C09)
: io 0x62,0x66
MCH (PNP0C01) at acpi0 not configured
attimer1 at acpi0 (TMR, PNP0100): io 0x40-0x43 irq 0
pckbc1 at acpi0 (PS2K, PNP0303) (kbd port): io 0x60,0x64 irq 1
pckbc2 at acpi0 (PS2M, SYN0A00) (aux port): irq 12
pcppi1 at acpi0 (SPKR, PNP0800): io 0x61
midi0 at pcppi1: PC speaker
sysbeep0 at pcppi1
COPR (PNP0C04) at acpi0 not configured
RMSC (PNP0C02) at acpi0 not configured
OMSC (PNP0C02) at acpi0 not configured
PCIE (PNP0C02) at acpi0 not configured
acpibat0 at acpi0 (BAT0, PNP0C0A-0): ACPI Battery
acpibat0: ASUS LION rechargeable battery
acpibat0: granularity: low->warn 0.052 Ah, warn->full 0.052 Ah
acpiacad0 at acpi0 (AC0, ACPI0003): ACPI AC Adapter
acpivga0 at acpi0 (VGA): ACPI Display Adapter
acpiout0 at acpivga0 (CRTD, 0x0100): ACPI Display Output Device
acpiout1 at acpivga0 (TVOD, 0x0200): ACPI Display Output Device
acpiout2 at acpivga0 (LCDD, 0x0400): ACPI Display Output Device
acpivga0: connected output devices:
acpivga0:   0x0100 (acpiout0): Ext. Monitor, head 0, bios detect
acpivga0:   0x0200 (acpiout1): TV, head 0, bios detect
acpivga0:   0x0400 (acpiout2): Unknown Output Device, head 0, bios detect
...
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o space, memory space enabled, rd/line, rd/mult, wr/inv ok
pchb0 at pci0 dev 0 function 0: vendor 8086 product 2590 (rev. 0x04)
agp0 at pchb0: i915-family chipset
agp0: detected 7932k stolen memory
agp0: aperture at 0xd0000000, size 0x10000000
i915drmkms0 at pci0 dev 2 function 0: vendor 8086 product 2592 (rev. 0x04)
drm: Memory usable by graphics device = 256M
drm: Supports vblank timestamp caching Rev 2 (21.10.2013).
drm: Driver supports precise vblank timestamp query.
drm: failed to find VBIOS tables
i915drmkms0: interrupting at ioapic0 pin 16 (i915)
drm: initialized overlay support
intelfb0 at i915drmkms0
intelfb0: framebuffer at 0xda0b0000, size 1920x1200, depth 32, stride 7680
DRM error in intel_pipe_config_compare: mismatch in adjusted_mode.flags(DRM_MODE_FLAG_NHSYNC) (expected 2, found 0)
warning: /iopt/src/sys/external/bsd/drm2/dist/drm/i915/intel_display.c:9894: pipe state doesn't match!
DRM error in intel_pipe_config_compare: mismatch in adjusted_mode.flags(DRM_MODE_FLAG_PHSYNC) (expected 0, found 1)
warning: /iopt/src/sys/external/bsd/drm2/dist/drm/i915/intel_display.c:9894: pipe state doesn't match!
wsdisplay0 at intelfb0 kbdmux 1: console (default, vt100 emulation), using wskbd0
wsmux1: connecting to wsdisplay0
vendor 8086 product 2792 (miscellaneous display, revision 0x04) at pci0 dev 2 function 1 not configured
...
wsdisplay0: screen 1 added (default, vt100 emulation)
wsdisplay0: screen 2 added (default, vt100 emulation)
wsdisplay0: screen 3 added (default, vt100 emulation)
wsdisplay0: screen 4 added (default, vt100 emulation)

on X startup:

drm: GMBUS [i915 gmbus vga] timed out, falling back to bit banging on pin 2
DRM error in intel_pipe_config_compare: mismatch in adjusted_mode.flags(DRM_MODE_FLAG_PHSYNC) (expected 0, found 1)
warning: /iopt/src/sys/external/bsd/drm2/dist/drm/i915/intel_display.c:9894: pipe state doesn't match!
DRM error in intel_pipe_config_compare: mismatch in adjusted_mode.flags(DRM_MODE_FLAG_PHSYNC) (expected 0, found 1)
warning: /iopt/src/sys/external/bsd/drm2/dist/drm/i915/intel_display.c:9894: pipe state doesn't match!

$ pcictl pci0 list
000:00:0: Intel 82915PM/GM/GMS,82910GML Host Bridge (host bridge, revision 0x04)
000:02:0: Intel 82915GM/GMS,82910GML Integrated Graphics Device (VGA display, revision 0x04)
000:02:1: Intel 82915GM/GMS IGD Companion (miscellaneous display, revision 0x04)
...