[Libdlo] GDM black screen / user and count meaning

[Alexander Todorov]

On  7.11.2010 18:44, Bernie Thompson wrote:

> Unfortunately, I don't have udlfb printing anything to the logs in
> dlfb_ops_blank(), or else I'd ask you to check dmesg if someone was
> errantly blanking the screen in that case.  If you wanted to add a
> dl_notice in that function, you could get more clues.
>

Hi Bernie,
I added the "BLANK:" message:

Nov  8 13:21:58 mini kernel: udlfb: open /dev/fb1 user=1 fb_info=dee3e000 count=1
Nov  8 13:21:58 mini kernel: udlfb: released /dev/fb1 user=1 count=0
Nov  8 13:21:58 mini kernel: udlfb: open /dev/fb1 user=1 fb_info=dee3e000 count=1
Nov  8 13:21:58 mini kernel: udlfb: open /dev/fb1 user=1 fb_info=dee3e000 count=2
Nov  8 13:21:58 mini kernel: udlfb: mmap() framebuffer addr:3777134592 size:1572864
Nov  8 13:21:58 mini kernel: udlfb: BLANK: /dev/fb1, blank_mode=1
Nov  8 13:21:58 mini kernel: udlfb: open /dev/fb2 user=1 fb_info=deca8000 count=1
Nov  8 13:21:58 mini kernel: udlfb: released /dev/fb2 user=1 count=0
Nov  8 13:21:58 mini kernel: udlfb: open /dev/fb2 user=1 fb_info=deca8000 count=1
Nov  8 13:21:58 mini kernel: udlfb: open /dev/fb2 user=1 fb_info=deca8000 count=2
Nov  8 13:21:58 mini kernel: udlfb: mmap() framebuffer addr:3780296704 size:1572864
Nov  8 13:21:58 mini kernel: udlfb: BLANK: /dev/fb2, blank_mode=1
Nov  8 13:21:59 mini kernel: udlfb: BLANK: /dev/fb1, blank_mode=0
Nov  8 13:21:59 mini kernel: udlfb: BLANK: /dev/fb2, blank_mode=0

This is after GDM has started. fb2 is now black.


After 1 minute Xorg goes into Standby mode (Option StandbyTime 1):

Nov  8 13:23:00 mini kernel: udlfb: BLANK: /dev/fb1, blank_mode=0
Nov  8 13:23:00 mini kernel: udlfb: BLANK: /dev/fb1, blank_mode=1
Nov  8 13:23:00 mini kernel: udlfb: BLANK: /dev/fb1, blank_mode=2
Nov  8 13:23:00 mini kernel: udlfb: BLANK: /dev/fb2, blank_mode=0
Nov  8 13:23:00 mini kernel: udlfb: BLANK: /dev/fb2, blank_mode=1
Nov  8 13:23:00 mini kernel: udlfb: BLANK: /dev/fb2, blank_mode=2

Then I wake it up by moving the mouse on both terminals:

Nov  8 13:23:19 mini kernel: udlfb: BLANK: /dev/fb1, blank_mode=0
Nov  8 13:23:19 mini kernel: udlfb: BLANK: /dev/fb1, blank_mode=0
Nov  8 13:23:22 mini kernel: udlfb: BLANK: /dev/fb2, blank_mode=0
Nov  8 13:23:22 mini kernel: udlfb: BLANK: /dev/fb2, blank_mode=0

> But another way -- when the problem happens again, we can you try writing 0 to
>
> /sys/class/graphics/fb1/blank
>

After testing several times so that the screen go black writing 0 to this file 
caused the monitor to come back. So it looks like you're correct.

Can you explain in more details what's happening here?


Regards,
Alexander.