Blank screen on resume

[Eric McCorkle]

Hello everyone,

It seems I'm plagued by blank screens on resume again on a different laptop... *sigh*

I've done quite a bit of diagnostic work on this, and there seem to be some clues, but I'm a bit stumped at this point.  The following github repo has patches that add extra logging, which has proven useful in my attempts to diagnose the issue: https://github.com/emc2/freebsd (sorry for distributing patches/logs in this way, but the logs are quite big).  Also in this repo, there's a pciconf, devinfo, and dmesg file.  The dmesg file shows the trace from booting a patched kernel in verbose mode then suspending it.

There's two main curiosities in the dmesg trace.  The first is that the power state of all the vgapci device seems to be 0 as opposed to 3 during resume, which was causing acpi_set_powerstate_method to skip resetting its power during resume.  I tried a simple patch (you can see it in the patch and its effects in the trace), but that didn't seem to work.  A second curiosity is that acpi_pwr_switch_consumer only seems to have an effect during resume.

The only other real lead I have is that the display doesn't seem to be active in acpi_video.  I'm not sure if this is an artifact of the efifb driver.

Lastly, I recall looking into vga bios calls from earlier such efforts.  I imagine there's something similar for efifb, but I've been unable to track down where this is happening.  Advice or information on that front would be much appreciated.

Best,
Eric