[Openchrome-devel] [Bug 96633] Odd Resolutions on DVI output

bugzilla-daemon at freedesktop.org bugzilla-daemon at freedesktop.org
Sat Jun 25 05:22:15 UTC 2016


--- Comment #8 from Kevin Brace <kevinbrace at gmx.com> ---
Hi Eric,

Just to be honest, fixing this bug is fairly tricky since I do not own a
monitor that can provide very detailed screen resolution information like the
one you own.
Yes, I did notice the blue line on the right side of the screen issue in CLE266
+ Samsung 23" monitor I have, but it was probably due to certain IGA1 registers
not being set correctly when OpenChrome took over setting up those registers (I
did not handle this correctly.).
One of the big problem OpenChrome still has is the fact that it is not
initializing all the registers, and this problem really can be traced back to
2005 or so when OpenChrome developers decided to rely on VBE to handle display
mode setting.
Even today, many internal registers are being initialized by VGA BIOS or VIA
frame buffer device driver.
I am adding more and more code to initialize all the relevant registers, but it
takes time to get it right, hence, you are seeing problems in the meantime.
VIA Technologies did not release all the relevant documents to write software
to properly program their hardware, hence, except for the 4 or so last devices
they shipped (CX700, VX800, VX855, and VX900), no official documentation is
This definitely makes my job harder than it should be.
    It appears that this "bug" is specific to IGA2, and just as a test, the
patch will "- 2" horizontal and vertical display count.
In order to apply the patch, you will download it to your xf86-video-openchrome
>From there, you will apply the patch.

patch -p1 < Proposed_Patch_IGA2_CrtcHDisplay_CrtcVDisplay_Both_Minus_2.patch

Then, compile and install OpenChrome.
I am hoping this will resolve the "1 dot off" screen resolution problem, or
give me hints for different things to try.

You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/openchrome-devel/attachments/20160625/ef6e4792/attachment.html>

More information about the Openchrome-devel mailing list