[Openchrome-devel] Getting ready to release OpenChrome Version 0.3.4

Kevin Brace kevinbrace at gmx.com
Thu Feb 18 05:15:13 UTC 2016

Hi Sebastian,

I do know why your laptop loses the LCD after standby mode resume.
This is because OpenChrome is not restoring or reinitializing certain LCD related extended VGA registers after it comes back from standby mode, at this point.
I figured this out around early December 2015 after analyzing the difference between before and after VGA register dump using via_regs_dump tool (I worked on this issue since July 2015.).
Fixing this will likely require some development work, so I will think that it will be fixed around OpenChrome Version 0.3.5 or 0.3.6.
    Fixing standby mode resume is a big deal to me, and this is what happened.
My laptop (Epic 1314, equivalent to MSI VR321 laptop) has VN896 chipset.
It has an LVDS LCD panel and external VGA connector.
By comparing the VGA register dump information, I figured out that Chrome 9 HC (the name of the graphics engine VN896 has) is getting certain registers reset when it comes out of standby.
So what I did was, I hard coded certain important registers related to LVDS LCD panel for secondary display controller to certain values, and now LCD is working after the computer comes back from standby.
However, there is one big problem.
Unfortunately, mouse cursor disappears on the LCD, and I still have not figured out how to get it back.
The only workaround I found was to use external VGA simultaneously with LVDS LCD panel, and mouse cursor comes back correctly for some reason.
VX800 probably has a different hardware for LVDS LCD, so it might work differently.
    The current OpenChrome code does not support extended display support, and I will imagine that this is a high priority feature to implement in the future other than fixing more bugs.


Kevin Brace

> Date: Fri, 12 Feb 2016 22:54:42 +0100
> From: Svenska <svenska-ml at arcor.de>
> To: openchrome-devel at lists.freedesktop.org
> Subject: Re: [Openchrome-devel] Getting ready to release OpenChrome
> 	Version 0.3.4
> Message-ID: <56BE54A2.4030002 at arcor.de>
> Content-Type: text/plain; charset=utf-8; format=flowed
> Hi,
> I have access to a Quanta IL1 compatible netbook, which is VX800-based. 
> It has a 800x480 LCD display and a VGA output.
> I can confirm that the display does not come back after suspend (usually 
> off, sometimes it turns on and fades to white). Also, on my system, 
> Openchrome does not support dualscreen (not enough Xrandr support).
> If you do some VX800-related changes, I could test them.
> About KMS... if it is working correctly, then the Modesetting driver 
> should work fine. What further benefits would the Openchrome X driver 
> provide on VX800 or newer chipsets? Since 3D and video decoding will 
> probably never be implemented, a KMS driver with xf86-video-modesetting 
> alone could work well.
> Best Regards,
> Sebastian

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