How does devuan choose which video drivers it uses?

alphalpha · 2021-09-30 15:28:38

So i always have a multiple drivers installed on my system, because i use the iso on multiple machines
vesa, intel, nouveau, radeon etc
Since there is no config file in /etc/X11 that specifically states what to use, i am actually not sure which one of those i might be using at the moment
It has always worked fine for me until last week when i had a new machine (old hardware) and i had to specifically tell it to use the intel driver
So i am asking myself, how does the system decide what to use when there is no config file?

hevidevi · 2021-10-09 13:04:38

https://wiki.debian.org/Xorg#Configure_X

Head_on_a_Stick · 2021-10-09 14:41:57

For the kernel drivers udev will (hopefully) detect the hardware and load the appropriate driver.

X also probes the hardware to determine the correct DDX & Mesa drivers. Don't use Xorg --configure, it's useless. Just write your own configuration snippets if you need to change any of the autodetected options.

EDIT: for Intel hardware you should be using the modesetting DDX driver because it's far less buggy than Intel's option. That's why you had to force the Intel driver

Last edited by Head_on_a_Stick (2021-10-09 14:43:15)

hevidevi · 2021-10-09 15:08:52

xorg -configure is not useless. You can use it to further tweak your X settings.

If it was useless then why is it a part of the Debian wikipedia.

If xorg.conf is missing for some reason, Xorg will probe your hardware on every startup. Though this works fine in most cases, some settings remain inaccessible. To create a starting point for customization, do the following.
Switch to a console as root (not a terminal emulator in X), then run:
# /etc/init.d/gdm stop || /etc/init.d/gdm3 stop || /etc/init.d/kdm stop || /etc/init.d/xdm stop || /etc/init.d/lightdm stop
$ cd /etc/X11/
# Xorg -configure

Last edited by hevidevi (2021-10-09 15:10:23)

Head_on_a_Stick · 2021-10-09 15:14:17

hevidevi wrote:

If it was useless then why is it a part of the Debian wikipedia.

Because the advice on that page is ancient and hasn't been updated to reflect the current situation.

All of the (DDX) video drivers supply their own configuration snippets that can be copied and modified as needed so there really is no need fot the --configure option at all.

EDIT:

empty@P14s:~ $ ls /usr/share/X11/xorg.conf.d/                                  
10-amdgpu.conf  10-quirks.conf  10-radeon.conf  40-libinput.conf  70-wacom.conf
empty@P14s:~ $

^ Copy any of those files to /etc/X11/xorg.conf.d/ and modify them as needed.

Last edited by Head_on_a_Stick (2021-10-09 15:16:36)

hevidevi · 2021-10-09 15:16:58

Head_on_a_Stick wrote:

hevidevi wrote:
If it was useless then why is it a part of the Debian wikipedia.
Because the advice on that page is ancient and hasn't been updated to reflect the current situation.
All of the (DDX) video drivers supply their own configuration snippets that can be copied and modified as needed so there really is no need fot the --configure option at all.

But it successfully describes the usage of X on my system.

hevidevi · 2021-10-09 15:19:21

Head_on_a_Stick wrote:

hevidevi wrote:
If it was useless then why is it a part of the Debian wikipedia.
Because the advice on that page is ancient and hasn't been updated to reflect the current situation.
All of the (DDX) video drivers supply their own configuration snippets that can be copied and modified as needed so there really is no need fot the --configure option at all.
EDIT:
empty@P14s:~ $ ls /usr/share/X11/xorg.conf.d/                                  
10-amdgpu.conf  10-quirks.conf  10-radeon.conf  40-libinput.conf  70-wacom.conf
empty@P14s:~ $
^ Copy any of those files to /etc/X11/xorg.conf.d/ and modify them as needed.

Okay and if some of those files are not present?

~ > ls /usr/share/X11/xorg.conf.d/
10-quirks.conf  40-libinput.conf  70-synaptics.conf

Last edited by hevidevi (2021-10-09 15:21:07)

Head_on_a_Stick · 2021-10-09 15:21:50

Write your own configuration snippet. It's not difficult.

EDIT: let's just agree to disagree about this and let the OP make their own mind up. I don't have the energy to argue.

Last edited by Head_on_a_Stick (2021-10-09 15:22:27)

hevidevi · 2021-10-09 15:22:51

Head_on_a_Stick wrote:

Write your own configuration snippet. It's not difficult.

So you are saying Xorg -configure is useless in my situation?

Head_on_a_Stick · 2021-10-09 15:27:49

What do you actually want to change?

hevidevi · 2021-10-09 15:30:36

Head_on_a_Stick wrote:

What do you actually want to change?

well that is not what the OP was asking, i dont want to change anything but Xorg -configure will give a conf file to see what is configured.

example:

Section "ServerLayout"
	Identifier     "X.org Configured"
	Screen      0  "Screen0" 0 0
	InputDevice    "Mouse0" "CorePointer"
	InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "Files"
	ModulePath   "/usr/lib/xorg/modules"
	FontPath     "/usr/share/fonts/X11/misc"
	FontPath     "/usr/share/fonts/X11/cyrillic"
	FontPath     "/usr/share/fonts/X11/100dpi/:unscaled"
	FontPath     "/usr/share/fonts/X11/75dpi/:unscaled"
	FontPath     "/usr/share/fonts/X11/Type1"
	FontPath     "/usr/share/fonts/X11/100dpi"
	FontPath     "/usr/share/fonts/X11/75dpi"
	FontPath     "built-ins"
EndSection

Section "Module"
	Load  "glx"
EndSection

Section "InputDevice"
	Identifier  "Keyboard0"
	Driver      "kbd"
EndSection

Section "InputDevice"
	Identifier  "Mouse0"
	Driver      "mouse"
	Option	    "Protocol" "auto"
	Option	    "Device" "/dev/input/mice"
	Option	    "ZAxisMapping" "4 5 6 7"
EndSection

Section "Monitor"
	Identifier   "Monitor0"
	VendorName   "Monitor Vendor"
	ModelName    "Monitor Model"
EndSection

Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz",
        ### <percent>: "<f>%"
        ### [arg]: arg optional
        #Option     "SWcursor"           	# [<bool>]
        #Option     "HWcursor"           	# [<bool>]
        #Option     "NoAccel"            	# [<bool>]
        #Option     "ShadowFB"           	# [<bool>]
        #Option     "VideoKey"           	# <i>
        #Option     "WrappedFB"          	# [<bool>]
        #Option     "GLXVBlank"          	# [<bool>]
        #Option     "ZaphodHeads"        	# <str>
        #Option     "PageFlip"           	# [<bool>]
        #Option     "SwapLimit"          	# <i>
        #Option     "AsyncUTSDFS"        	# [<bool>]
        #Option     "AccelMethod"        	# <str>
        #Option     "DRI"                	# <i>
	Identifier  "Card0"
	Driver      "nouveau"
	BusID       "PCI:1:0:0"
EndSection

Section "Screen"
	Identifier "Screen0"
	Device     "Card0"
	Monitor    "Monitor0"
	SubSection "Display"
		Viewport   0 0
		Depth     1
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     4
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     8
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     15
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     16
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     24
	EndSubSection
EndSection

Last edited by hevidevi (2021-10-09 15:35:41)

Head_on_a_Stick · 2021-10-09 15:37:44

From the man page (added emphasis):

-configure
When this option is specified, the Xorg server loads all video
drive modules, probes for available hardware, and writes out
an initial xorg.conf(5) file based on what was detected. This
option currently has some problems on some platforms, but in
most cases it is a good way to bootstrap the configuration
process.

So watch out for that

hevidevi · 2021-10-09 15:42:48

Head_on_a_Stick wrote:

From the man page (added emphasis):
-configure
When this option is specified, the Xorg server loads all video
drive modules, probes for available hardware, and writes out
an initial xorg.conf(5) file based on what was detected. This
option currently has some problems on some platforms, but in
most cases it is a good way to bootstrap the configuration
process.
So watch out for that

Pays to read the documentation, what platforms?

Head_on_a_Stick · 2021-10-09 15:46:59

Doesn't say.

I don't like the -configure option for the same reason I don't like most abstractions — they introduce the possibility of new bugs and vulnerabilities whilst adding no new features. Why would anybody want that?

hevidevi · 2021-10-09 15:55:38

Head_on_a_Stick wrote:

Doesn't say.
I don't like the -configure option for the same reason I don't like most abstractions — they introduce the possibility of new bugs and vulnerabilities whilst adding no new features. Why would anybody want that?

Ive never had an issue with it, maybe newer hardware might.

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#1 2021-09-30 15:28:38

How does devuan choose which video drivers it uses?

#2 2021-10-09 13:04:38

Re: How does devuan choose which video drivers it uses?

#3 2021-10-09 14:41:57

Re: How does devuan choose which video drivers it uses?

#4 2021-10-09 15:08:52

Re: How does devuan choose which video drivers it uses?

#5 2021-10-09 15:14:17

Re: How does devuan choose which video drivers it uses?

#6 2021-10-09 15:16:58

Re: How does devuan choose which video drivers it uses?

#7 2021-10-09 15:19:21

Re: How does devuan choose which video drivers it uses?

#8 2021-10-09 15:21:50

Re: How does devuan choose which video drivers it uses?

#9 2021-10-09 15:22:51

Re: How does devuan choose which video drivers it uses?

#10 2021-10-09 15:27:49

Re: How does devuan choose which video drivers it uses?

#11 2021-10-09 15:30:36

Re: How does devuan choose which video drivers it uses?

#12 2021-10-09 15:37:44

Re: How does devuan choose which video drivers it uses?

#13 2021-10-09 15:42:48

Re: How does devuan choose which video drivers it uses?

#14 2021-10-09 15:46:59

Re: How does devuan choose which video drivers it uses?

#15 2021-10-09 15:55:38

Re: How does devuan choose which video drivers it uses?

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