xserver deelopments

Bill Spitzak spitzak at gmail.com
Wed Aug 21 12:50:47 PDT 2013

Since you seem to be working on the xserver, I was wondering if you 
could address some problems I have been having.

I think my underlying difficulty is that I have to use the wlshm driver 
rather than the default of wlegl. This requires me to find an xorg.conf 
file setting the driver to wlshm. This requires an environment variable 
to be changed between when I run X and when I run wayland (if I want to 
try xwayland under wayland running in an X window).

I am very suspicious of what data in an xorg.conf and xorg.conf.d file 
will do to the xwayland server if it was not intended for it. It is 
obvious from tracing the code that the xwayland driver is parsing the 
file and setting lots of internal data structures from it. I find it 
highly unlikely that the xwayland driver is actually ignoring every bit 
of the resulting state, thus random xorg.conf files can produce 
unexpected internal states and strange bugs that I would think the 
xwayland developers would prefer not to have to fix.

One known thing this prevents is the ability to test the default config 
compiled into xwayland. It will *always* find /etc/X11/xorg.conf if it 

I have posted several times a patch to change the name of the file from 
xorg.conf to xwayland.conf (and xwayland.conf.d). For most users this 
would cause x under wayland to use the default configuration. If 
configuration is really needed (for instance to set the wlshm driver) 
then I can create an xwayland.conf file to set only this and not break 
my X server. This patch has been rejected by Kristian with a claim that 
the driver is ignored because it is somehow recognized as not being a 
wayland driver. This however does not address my need for the wlshm 
driver or my worry about what hundreds of lines messing with input and 
output devices and other settings will do to xwayland. Do you have any 
opinion on this?

Another thing I was thinking of looking into is to merge the wlshm code 
into the wlegl driver, similar to how the toytoolkit will use shm if egl 
fails. This would allow the default driver to work, so in theory if the 
claim that reading xorg.conf is harmless then it will work for me 
without hiding the config file. Also it appears there are numerous bugs 
in wlshm that have been fixed in wlegl.

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