On Monday 26 March 2012 14:22:02 Chris Wilson wrote: > On Thu, 15 Dec 2011 13:46:28 +0100, Helge Bahmann <helge.bahmann at secunet.com> wrote: > > Hi everyone, > > > > would you mind putting something along the following into > > xf86-video-intel? > > A few months later... I looked at this and concluded that it is just > working around a kernel bug, which I'm always optimistic will be > resolved in the next release. > -Chris Most likely there is a "bug" in my understandig of how X-Server and drm console layer are supposed to cooperate: - how does the kernel layer reliably distinguish between the states "userspace manages display heads vs. "kernel console layer manages display heads" ? - how does the kernel layer reliably detect the "ground state" from which userspace starts setting up things ? - what assumptions may user-space make on the "left-over" state when it takes over responsibility? I don't think kernel code currently handles these issues too well, resulting in a number of odd corner cases when plugging/unplugging displays at the "right" times (while switched away from X, while in suspend-to-ram state, while X server resumes but is slow to re-setup things because it got paged out...). My best shot at fixing this was to have X not make too many assumptions on the state after taking over, and bring everything into a well-defined state. Could you perhaps briefly explain how the interaction is supposed to look? I would really like to provide a more "correct" fix, but I don't fully grasp the intended model so far. Best regards Helge -- Dr.-Ing. Helge Bahmann Berater Gesch?ftsbereich Hochsicherheit secunet Security Networks AG Ammonstra?e 74 01067 Dresden, Germany Fon: +49 201 54 54-3586 Fax: +49 201 54 54-1323 Email: helge.bahmann at secunet.com Sitz: Kronprinzenstra?e 30, 45128 Essen Amtsgericht Essen HRB 13615 Vorstand: Dr. Rainer Baumgart, Thomas Koelzer, Thomas Pleines Aufsichtsratsvorsitzender: Dr. Karsten Ottenberg
