[elrepo] nvidia driver with EL 7.4 (Xorg 1.19) and multiple monitors

[Phil Perry]

On 14/12/17 19:31, Derek Schrock wrote:
> On Sat, Dec 09, 2017 at 06:51:37PM EST, Derek Schrock wrote:
>> Anyone using the elrepo nvidia driver with EL 7.4 (RHEL so far tested)
>> and newly included Xorg 1.19 with multiple monitors?  Before 7.4 our
>> experience with multimonitor (2+) support with the default elrepo
>> install of kmod-nvidia and nvidia-x11-drv for a linear layout (1xN) the
>> simple xorg.conf (just the device entry) created by the elrepo package
>> the monitor layout would remain static based off the cabling and not
>> alternate or change.  Is this expected behavior or have we just been
>> very lucky with < EL 7.4?
>>
>> So far with out testing of RHEL 7.4 and 375.66 384.90 and 384.98 is that
>> once you log out of your GUI session the display layout will rotate,
>> shift, or change.   Is anyone else able to reproduce this?
>>
>> If we create an xorg.conf that sets the layout this seems to fix the
>> issue however we distribute a large number of GUI workstations to remote
>> locations that might require a different xorg.conf per-location or even
>> per-machine.
>>
>> An example of what we're seeing with three displays DFP-4/5/6
>> At startup: DFP-4, DFP-5, DFP-6 mousing left to right 4, 5, 6
>> Logout: DFP-5, DFP-4, DFP-6 mousing left to right 5, 4, 6
>> Logout: DFP-6, DFP-4, DFP-5 mousing left to right 6, 4, 5
>> ....
>>
>> I don't see a pattern to it other than it's just changing.
>>
>> Right now I think it's something with Xorg 1.19 however it could be
>> something driver plus 1.19 related.   I don't believe it's elrepo
>> specific but looking for feedback from users that are using 7.4 or if
>> our previous experience is expected behavior.
> 
> You can see the solution to this issue here:
> 
> https://devtalk.nvidia.com/default/topic/1027427/linux/nvidia-384-98-and-display-orientation-chaning-when-x-restarts-layout-less-xorg-conf/post/5226491/#5226491
> 
> It's possible for some older hardware the kernel param
> nvidia-drm.modeset=1 needs set.  We're using NVS 510s.


Thanks Derek, useful to know, and glad you got it fixed.