On 22 February 2016 at 22:20, Michael Thayer <michael.tha...@oracle.com> wrote: > On 19.02.2016 16:16, Michael Thayer wrote: >> >> I have been experimenting a bit with plugging and unplugging of graphics >> devices (using a dummy KMS driver which is udl stripped of the actual >> hardware poking) and how the X server copes with that. It seems to cope >> well with a secondary device being removed, but not with the only >> graphics device in the system disappearing (in that case the >> hot-pluggable device is not deemed to be a GPU device, and therefore not >> removable if I understood what is happening correctly). >> >> This is interesting for me because I am looking at putting a KMS driver >> for the VirtualBox video device into the upstream kernel, but would like >> to be able to update the driver at run-time, so that we are not stuck >> with whatever version some guest distribution which is no longer being >> updated happens to provide. My first idea for handling this was to >> simulate a device unplug so that the old driver could be removed and the >> new one added. (Not sure if I am handling the hotplug right in the >> vboxvideo driver yet of course, but I assume that my dummy driver, which >> just copies code from udl, does get it right.) >> >> I will take a look at this when I get a chance of course, but I thought >> I would write to the list before that in case anyone else has thoughts, >> ideas or fixes (potenially including how I could better handle the >> driver update). > > > Re-reading the X server code a couple of days later makes it clear that this > is intended. The question is how I should best deal with this. Would people > be open to having the first graphics device hot-removable too? Obviously > there are other use cases for this, like using DisplayLink with a headless > embedded device. But I realise that the X server was designed with the > assumption that this will not happen. Any other suggestions? I doubt > having a dummy first device which can stay in place would go down well > elsewhere. >
Install driver, ask user to reboot. Trying to remove the first screen from X is a long and insanity inspiring process. I've spent months hacking up something that lets us migrate stuff from screen A to screen B, but it's really messy and the current X server code doesn't lend itself to it at all, so I pretty much gave up the last time I tried. Dave. _______________________________________________ xorg-devel@lists.x.org: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: https://lists.x.org/mailman/listinfo/xorg-devel