Bug 81951

Created attachment 145901 [details]
DSA-3020 dmesg with ""video=DVI-D-1:1920x1080D"

I've just been assisting a user with an Advantech DSA-3020 board [1][user manual] which
has the Poulsbro chip-set and uses the gma500_gfx driver on a small embedded server currently running Ubuntu 14.04.1 LTS.

The device has 2 outputs: LVDS-1 and DVI-D-1. Nothing is connected to LVDS-1. A 1920x1080 monitor is connected to DVI-D-1.

During POST and bootloader the display is on DVI-D-1. As soon as gma500_gfx initialises the DVI-D-1 display reports "No Signal". Nothing we've done in diagnosing this has helped.

One workaround is to blacklist gma500_gfx and allow the vesafb driver to handle the GPU. The other is to totally disable ACPI in BIOS. If ACPI is enabled in BIOS but disabled in the OS ("acpi=off") the symptoms still occur. Disabling ACPI is not acceptable since other issues arise.

We found:

/sys/class/drm/card0-DVI-D-1/enabled=disabled
/sys/class/drm/card0-DVI-D-1/status=connected
/sys/class/drm/card0-LVDS-1/enabled=disabled
/sys/class/drm/card0-LVDS-1/status=connected

We used "video=DVI-D-1:1920x1080D video=LVDS-1:1920x1080e" (both independently and together) but there was no improvement despite:

[drm] forcing DVI-D-1 connector ON

/sys/class/drm/card0-DVI-D-1/dpms=On
/sys/class/drm/card0-DVI-D-1/edid=<... Samsung EDID block ...>
/sys/class/drm/card0-DVI-D-1/enabled=enabled
/sys/class/drm/card0-DVI-D-1/modes=1920x1080
1920x1080
1920x1080
1920x1080
1920x1080
1920x1080
1920x1080
1920x1080
1680x1050
1600x900
1280x1024
1280x1024
1440x900
1366x768
1280x800
1152x864
1280x720
1280x720
1280x720
1024x768
1024x768
1024x768
832x624
800x600
800x600
800x600
720x576
720x480
720x480
640x480
640x480
640x480
640x480
640x480
720x400
/sys/class/drm/card0-DVI-D-1/status=connected
/sys/class/drm/card0-DVI-D-1/uevent=
/sys/class/drm/card0-LVDS-1/dpms=On
/sys/class/drm/card0-LVDS-1/edid=
/sys/class/drm/card0-LVDS-1/enabled=enabled
/sys/class/drm/card0-LVDS-1/modes=800x600
/sys/class/drm/card0-LVDS-1/status=connected
/sys/class/drm/card0-LVDS-1/uevent=

We also tried "vbetool dpms off".


[1] http://support.elmark.com.pl/advantech/pdf/DSA-3020man.pdf