<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - Tearing with reverse prime (intel primary, nouveau secondary)" href="https://bugs.freedesktop.org/show_bug.cgi?id=103202#c3">Comment # 3</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - Tearing with reverse prime (intel primary, nouveau secondary)" href="https://bugs.freedesktop.org/show_bug.cgi?id=103202">bug 103202</a> from <a class="email" href="mailto:post+fdo@ralfj.de" title="post+fdo@ralfj.de">post+fdo@ralfj.de</a> <pre>> I'm told that tearing with reverse prime is expected. That would still be a bug then though? Clearly some form of synchronization should be supported. It seems there is some work on getting synchronization to work with PRIME <<a href="https://www.x.org/wiki/Events/XDC2016/Program/xdc-2016-prime-sync.pdf">https://www.x.org/wiki/Events/XDC2016/Program/xdc-2016-prime-sync.pdf</a>>; not sure what the current status of that is. Some sites make it sound like using the NVidia card with the proprietary drivers as primary actually can get you V-sync on both screens, so is this just a matter of getting the nouveau DRM driver hooked up to that infrastructure? > if you were to flip them around and run the nvidia board as primary, you'd see tearing on the intel-connected screen. Possible; I would then also have really bad battery life with no external screen connected as the NVidia card would keep running. > -intel/radeon both offer the option to stage that copy into a back buffer for flipping to avoid the tear Given that the Intel card is the primary here, that wouldn't really help, right? I would expect to need such an option for whatever drives the NVidia card. > X tears by default. Well, yes, but with reverse PRIME I get tearing even if the application uses V-Sync or if I use a compositor. So, this is not about a lack of synchronization per default, it is about synchronization never happening even when using the appropriate APIs. I wouldn't mind looking into Wayland, but found no indication that reverse PRIME is supported there at all.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>