On Mon, Oct 22, 2012 at 03:39:36PM +0100, Alan Cox wrote:
> > [  689.950596] gma500 0000:00:02.0: Backlight lvds set brightness 7a127a12
> > [  689.950627] [drm] Initialized gma500 1.0.0 2011-06-06 for 0000:00:02.0 on minor 0
> 
> It's got the LVDS configured it seems and the brightness was already set
> up. That should be harmless.
> 
> > Besides the VGA the driver detects a LVDS as well although there's none
> > attached (the board does have a connector for it though):
> 
> Ok so it finds both ports which is what I would expect
> 
> > # grep -l ^connected /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-*/status
> > /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/status
> > /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-VGA-1/status
> 
> This means it found there was a VGA port and from
> psb_intel_sdvo_output_setup called psb_intel_sdvo_analog_init.
> 
> > 
> > It also states that both ports are disabled:
> 
> Which would explain the black screen.
> 
> > 
> > # cat   /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-*/enabled
> > disabled
> > disabled
> > 
> > I didn't find a way to enable any of these ports via sysfs and X.org's
> > modesetting driver fails either. Any pointers on howto debug this
> > further are greatly appreciated.
> 
> My first guess would be that the detection of the VGA failed. That would
> explain all your symptoms and since it relies on the firmware...
> 
> First thing to do is turn drm debug on in full and you should then get a
> dump of the SDVO capabilities, particulary output_flags as well as an
> entry giving the clock range etc if it initialized it ok.

The list of probed modes looks sane:

[    5.059963] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:45:VGA-1] probed modes :
[    5.059978] [drm:drm_mode_debug_printmodeline], Modeline 48:"1920x1080" 60 148500 1920 2008 2052 2200 1080 1084 1089 1125 0x48 0x5
[    5.060054] [drm:drm_mode_debug_printmodeline], Modeline 53:"1600x1200" 60 162000 1600 1664 1856 2160 1200 1201 1204 1250 0x40 0x5
[    5.060093] [drm:drm_mode_debug_printmodeline], Modeline 54:"1680x1050" 60 146250 1680 1784 1960 2240 1050 1053 1059 1089 0x40 0x6
[    5.060129] [drm:drm_mode_debug_printmodeline], Modeline 84:"1680x945" 60 131481 1680 1784 1960 2240 945 946 949 978 0x0 0x6
[    5.060163] [drm:drm_mode_debug_printmodeline], Modeline 75:"1400x1050" 75 156000 1400 1504 1648 1896 1050 1053 1057 1099 0x40 0x6
[    5.060200] [drm:drm_mode_debug_printmodeline], Modeline 74:"1400x1050" 60 121750 1400 1488 1632 1864 1050 1053 1057 1089 0x40 0x6
...
[    5.060935] [drm:drm_setup_crtcs], 
[    5.060951] [drm:drm_enable_connectors], connector 7 enabled? yes
[    5.060966] [drm:drm_enable_connectors], connector 11 enabled? no
[    5.060979] [drm:drm_enable_connectors], connector 28 enabled? no
[    5.060993] [drm:drm_enable_connectors], connector 45 enabled? yes
[    5.061006] [drm:drm_target_preferred], looking for cmdline mode on connector 7
[    5.061019] [drm:drm_target_preferred], looking for preferred mode on connector 7
[    5.061033] [drm:drm_target_preferred], found mode 1024x768
[    5.061045] [drm:drm_target_preferred], looking for cmdline mode on connector 45
[    5.061058] [drm:drm_target_preferred], looking for preferred mode on connector 45
[    5.061071] [drm:drm_target_preferred], found mode 1920x1080
[    5.061083] [drm:drm_setup_crtcs], picking CRTCs for 2048x2048 config
[    5.061106] [drm:drm_setup_crtcs], desired mode 1024x768 set on crtc 4
[    5.061126] [drm:drm_setup_crtcs], desired mode 1920x1080 set on crtc 3
[    5.061451] [drm] Initialized gma500 1.0.0 2011-06-06 for 0000:00:02.0 on minor 0
[    5.160076] [drm:psb_lid_timer_func], LVDS panel never powered up

and there's also enabled connectors according to the debug output. I
tried to get a clue from the source where these get disabled but without
any luck yet. I've attached the full debug output. 
Cheers,
 -- Guido


> 
> Alan
>