Re: Xorg testing and configuration, Xorg drivers, and Mesa drivers

On Sat, Apr 20, 2019 at 08:58:13PM +0000, Hans Malissa wrote:
> I'm trying to understand the various input and video drivers as well as hardware video acceleration for Xorg, and also the Mesa drivers, and how all of it interacts.
> So, in http://linuxfromscratch.org/blfs/view/stable-systemd/x/x7driver.html we installed all sorts of input and video drivers for Xorg, as well as some hardware video acceleration packages. And on the page on Xorg Testing and Configuration, http://linuxfromscratch.org/blfs/view/stable-systemd/x/xorg-config.html, we primarily rely on Xorg to figure out the drivers itself. So how can I find out which input and video drivers Xorg is using? And how do I know which hardware video acceleration packages it's taking advantage of?
> Also, what does this have to do with the specific video drivers installed by Mesa (http://linuxfromscratch.org/blfs/view/stable-systemd/x/mesa.html)?
> Greetings,
> 
> Hans

For the Xorg video drivers, look at the Xorg log.

e.g. on this machine -
[    20.441] (II) Module glx: vendor="X.Org Foundation"
[    20.441]    compiled for 1.20.3, module version = 1.0.0
[    20.441]    ABI class: X.Org Server Extension, version 10.0
[    20.441] (II) Applying OutputClass "Radeon" to /dev/dri/card0
[    20.441]    loading driver: radeon
[    20.441] (==) Matched radeon as autoconfigured driver 0
[    20.441] (==) Matched ati as autoconfigured driver 1
[    20.441] (==) Matched modesetting as autoconfigured driver 2
[    20.441] (==) Matched fbdev as autoconfigured driver 3
[    20.441] (==) Matched vesa as autoconfigured driver 4

NB I do not have all of those installed.  That is the full list of
Xorg video drivers which will be *considered* for this particular
hardware.

For input drivers: if you built libinput, I think that will be used
by default - but you can specify the driver in the Driver part of a
keyboard conf file.  Again, look at the Xorg log, specifically the
LoadModule lines - that should show either "libinput" or "evdev"
(not to be confused with the xkb_model which is probably "evdev" for
both).

For video acceleration - that is a harder question, different
applications might use different things.  I usually draw the line at
running 'glxinfo -B' which merely tells me

    Accelerated: yes

among its other information.


ĸen
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