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
Unfortunately for a board and BIOS ACPI setting specific bug like that you'd pretty much need someone in front of the board to debug it. Poulsbo uses an Imagination graphics core so there is no documentation and the driver is built out of bits that were required to be released under the GPL, and a lot of trial/error and guesswork. If there is some kind of bridge or external logic that has magic power hooks not in the code that it was developed from then you are basically out of luck