Bug#169308: xserver-xfree86: LCD blanks and won't unblank -> kernel bug?
I read this in Kernel Traffic #192. Could this be your problem?
1. Linux 2.4.20-rc1 Released
Topics: Filesystems, Framebuffer, Source Control
29 Oct - 8 Nov (8 posts) Archive Link: "Linux 2.4.20-rc1"
Marcelo Tosatti announced 2.4.20-rc1 and included the BitKeeper summary. He
said, "Several networking fixes, net drivers fixes, devfs root boot option
fixed, and more." Carl-Daniel Hailfinger reported that his system would come
back up with a blank screen after a hardware suspend and resume. Switching
to another console and back again would fix it. He traced the problem to
2.4.18-pre7, in the power management code; and Marcelo asked if he'd
actually reverted the part of the code he'd identified. Carl tried this and
found that his initial assessment was wrong. Instead, he traced the problem
all the way back to some framebuffer changes in 2.4.18-pre1. He posted a
patch to revert the change, then posted a shorter refined version. This was
enough to lead Benjamin Herrenschmidt in the right direction. Benjamin said:
Ok, I'm the one to blame for that patch.
It was intended to fix some problems where the console subsystem
would call fbcon_blank after the fbdev HW was put to suspend, thus
crashing the system.
This should really be fixed in the low level fb drivers to ignore
blanking when they are asleep though. This is a kind of hack as 2.4
lacks a proper model for ordering power management requests
Marcelo, feel free to delete those 4 lines (but not the whole
patch), just the 4 lines in fbcon_blank, I'll make sure the various
drivers are made safe.