<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_REOPENED " title="REOPENED --- - three monitors on two radeon cards works with some layouts not others" href="https://bugs.freedesktop.org/show_bug.cgi?id=81476#c20">Comment # 20</a> on <a class="bz_bug_link bz_status_REOPENED " title="REOPENED --- - three monitors on two radeon cards works with some layouts not others" href="https://bugs.freedesktop.org/show_bug.cgi?id=81476">bug 81476</a> from <a class="email" href="mailto:agd5f@yahoo.com" title="Alex Deucher <agd5f@yahoo.com>"> Alex Deucher</a> <pre>(In reply to <a href="show_bug.cgi?id=81476#c19">comment #19</a>) > > I'd believe it as a hardware limitation if inverting the first two monitors > didn't fix it. If I were willing to physically turn my first two monitors > upside-down, it would work fine with the given hardware. The hardware can > display across my three monitors at 4800x1200 as long as two of the screens > are inverted. We just need to make the software put those screens into the > hardware the other way up! As I said before, it only works with rotation because it's scanning out of different buffers when rotation is enabled. When you enable rotation a shadow buffer is created which is a rotated duplicate of the sub-region of the entire desktop. So for the rotated case, the display hw is scanning out of a 1600x1200 surface rather than the full 4800x1200 surface. If you wanted to you could do something similar for the non-rotated case in the xserver, but that would incur an extra copy for every update of the desktop in the non-rotated case. If you want to test further, try and disable acceleration (Option "NoAccel" "true" in the device section of your xorg.conf) or use the modesetting driver (xf86-video-modesetting). You won't be able to use rotation since that requires acceleration do to the rotated blit, but that will take all non-display hw factors (3D, etc.) out of the equation.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>