Bug 94844

Summary:	Ditching xf86-video-nouveau in favor of xf86-video-modesetting?
Product:	xorg	Reporter:	N. W. <nw9165-3201>
Component:	Driver/nouveau	Assignee:	Nouveau Project <nouveau>
Status:	RESOLVED NOTABUG	QA Contact:	Xorg Project Team <xorg-team>
Severity:	normal
Priority:	medium
Version:	unspecified
Hardware:	All
OS:	All
Whiteboard:
i915 platform:		i915 features:

Description N. W. 2016-04-06 12:22:58 UTC

Hello,

according to the discussion in the following Phoronix forum thread:

https://www.phoronix.com/forums/forum/phoronix/latest-phoronix-articles/863332-intel-s-unreleased-3-0-x-org-driver-gets-more-fixes-for-dri3-present

the generic xf86-video-modesetting DDX driver included in xorg-server seems to be better than most vendor specific xf86-video- drivers.

I am wondering:

Then why not ditch xf86-video-nouveau in favor of xf86-video-modesetting?

Regards

Comment 1 poma 2016-04-06 12:51:40 UTC

https://nouveau.freedesktop.org/wiki/Bugs/
"... We also have a mailing list where you can ask questions, discuss patches or whatever is related to nouveau and its tools."

https://lists.freedesktop.org/mailman/listinfo/nouveau

Comment 2 Ilia Mirkin 2016-04-06 13:33:16 UTC

https://xkcd.com/386/

(a) GLAMOR accel would only work on G80+, nouveau supports Riva TNT2 and up.
(b) xf86-video-nouveau is well tested and simple, the GL driver is complex and causes crashes for a lot of people
(c) Many people choose not to install nouveau's GL driver (for improved stability), would now be stuck without acceleration
(d) GLAMOR happens to trigger some bugs in nouveau's GL impl that I've been unable to track down

Look at all the trouble Maxwell has had as a result of not having a dedicated EXA impl in xf86-video-nouveau and being stuck with modesetting/glamor.

Comment 3 Ben Skeggs 2016-04-06 22:02:41 UTC

(In reply to Ilia Mirkin from comment #2)
> https://xkcd.com/386/
> 
> (a) GLAMOR accel would only work on G80+, nouveau supports Riva TNT2 and up.
> (b) xf86-video-nouveau is well tested and simple, the GL driver is complex
> and causes crashes for a lot of people
> (c) Many people choose not to install nouveau's GL driver (for improved
> stability), would now be stuck without acceleration
> (d) GLAMOR happens to trigger some bugs in nouveau's GL impl that I've been
> unable to track down
> 
> Look at all the trouble Maxwell has had as a result of not having a
> dedicated EXA impl in xf86-video-nouveau and being stuck with
> modesetting/glamor.

(d) is no longer an issue it seems, I've been running in this configuration for weeks now and the two issues that used to appear no longer do.  I'm not entirely sure it was our bug, and not just glamor doing something inappropriate.

Personally, I'm all for using -modesetting on >=G80 and no longer plan on maintaining -nouveau beyond bug fixes.  So, new hardware, and MST support will require -modesetting unless someone else does the work.

Comment 4 N. W. 2016-04-07 17:16:35 UTC

This has made it to the news, see:

http://www.phoronix.com/scan.php?page=news_item&px=Nouveau-Vs-Modesetting

;D

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