[Libdlo] Blanking Support on mimo 740

[justin at dynam.ac]

Hi All,
I've managed to get a Mimo 740 running under my FC12 install with no
problem using the latest udlfb code from the git Repository.

I'm using this setup at the moment with a Embedded version of a QT
application, that uses the framebuffer console directly. No problems
(mostly) at all there.

The only issue I have currently:

Blanking Support (via the sysfs path: /sys/class/graphics/fb1/blank) is
not working at all. I'm trying to write a basic screensaver for my QT app
that will enable blanking, but before I even started on that I thought I
would test out blanking support.

I've put some debug statements into the udlfb.c file for the dlfb_blank
function to check its getting called and the dlfb_sync_bulk_msg call
returns successfully. This is what I'm getting:

usb 1-4.2: dlfb: open /dev/fb1 user=1 count=1
usb 1-4.2: dlfb: dlfb_sync_bulk_msg Returned 0
usb 1-4.2: dlfb: Blank /dev/fb1 Blank 0
usb 1-4.2: dlfb: dlfb_sync_bulk_msg Returned 0
usb 1-4.2: dlfb: Blank /dev/fb1 Blank 3
usb 1-4.2: dlfb: dlfb_sync_bulk_msg Returned 0
usb 1-4.2: dlfb: Blank /dev/fb1 Blank 1
usb 1-4.2: dlfb: dlfb_sync_bulk_msg Returned 0
usb 1-4.2: dlfb: Blank /dev/fb1 Blank 2
usb 1-4.2: dlfb: dlfb_sync_bulk_msg Returned 0
usb 1-4.2: dlfb: Blank /dev/fb1 Blank 3
usb 1-4.2: dlfb: dlfb_sync_bulk_msg Returned 0
usb 1-4.2: dlfb: Blank /dev/fb1 Blank 0

But nothing happens to the MIMO. I thought it might have something to do
with a application "opening" on/dev/fb1, but even when closing my app, I'm
still not getting any results.

Anything else I can provide to help diagnose this problem?

On a side note, and maybe for a latter email, I'm also getting horizontal
artifacts on the screen after several hours of operations. Reading the
archives, I saw someone else post on this, and there was a thought there
was a race condition on the memmap. This is very reproducible for me
(takes about 1 hour though) so if I can provide further info to help debug
that, I'm willing to take on the challenge!

One last question and I'm not sure if its even supported on these
displaylink devices, but can we implement software backlight control? If
someone knows the command/registers, I'm more than willing to have a stab
at implementing it (my first venture into Kernel Programming though...)

Cheers

Justin