Obtaining Xorg DDX commit privilege

[Kevin Brace]

Hi Adam,

I was thinking that it is not really desirable to let VBE start tinkering with I2C bus related registers this early in the PreInit callback, and besides that, if r128 is being used on PowerPC (or Alpha or SPARC) platform, there is no INT 10H VBE.
Furthermore, in order to detect plethora of display devices, a lot more hardware initialization often have to happen, and I did not think it was desirable for that to occur this early within PreInit callback.

Kevin Brace
Brace Computer Laboratory blog
https://bracecomputerlab.com


> Sent: Wednesday, June 06, 2018 at 12:06 PM
> From: "Adam Jackson" <ajax at nwnk.net>
> To: "Kevin Brace" <kevinbrace at gmx.com>, xorg-devel at lists.x.org, "Connor Behan" <connor.behan at gmail.com>
> Cc: "\"Michel\" Dänzer" <michel at daenzer.net>
> Subject: Re: Obtaining Xorg DDX commit privilege
>
> On Wed, 2018-06-06 at 00:37 +0200, Kevin Brace wrote:
> 
> > Regarding patch #5, it is based on the observation that starting X
> > Server with probing option does not really do anything inside PreInit
> > recall back, hence, there is no need to probe the monitor via VBE.
> 
> This pattern is common among the UMS drivers. The idea was to
> initialize enough of the ConfiguredMonitor variable that X -configure
> could write out a maybe-reasonable monitor section, which the user
> would then edit fine tune. This turns out to be fairly pointless now
> that we can construct the valid mode list at runtime, which is why
> RANDR 1.2 drivers typically don't do this bit. (Also because vbe is
> sort of intrinsically single-headed, so "a" configured monitor isn't
> really meaningful.)
> 
> - ajax
>