On Thu, Aug 30, 2012 at 8:24 AM, Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxx> wrote: > > Hi all, > > I've been playing with some DisplayLink adapters, six of them to be precise > connected to six identical HDMI monitors. > > Under kernel 3.5 things did not really work for me apparently because of the > udl driver's inability to fetch EDID. Interestingly, logged EDID blocks were > different for each of the six monitors which suggests a serious bug somewhere. > > I've then went to see if I can load my own EDID, because I remember doing it > via /sys/class/graphics/fb?/edid before, but that file was not there. > (Is it possible to override EDID with the udl driver?) > > To cut the long story short, I figured out there are two drivers for this > hardware. Fedora based 3.5 kernel builds and uses udl, while the older 3.3.2 > I played with before builds and uses udlfb. (Why two drivers?) udlfb was the original driver. It's a basic kernel fb driver. udl is a drm driver that Dave wrote based on udlfb. The drm variant will eventually allow you to hotplug displaylink adapters in X and use acceleration provided by another GPU. > > Now going back to 3.3.2 and udlfb, EDID got correctly fetched from all six > monitors. Sounds like a bug in the udl i2c code. Probably worth comparing the relevant udl and uldfb code; it may be a simple fix. Alex _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
