<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - Macbook pro 11,5 screen flicker when AC adapter plugged in" href="https://bugs.freedesktop.org/show_bug.cgi?id=98897#c9">Comment # 9</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - Macbook pro 11,5 screen flicker when AC adapter plugged in" href="https://bugs.freedesktop.org/show_bug.cgi?id=98897">bug 98897</a> from <a class="email" href="mailto:tom@r.je" title="Tom B <tom@r.je>"> Tom B</a> <pre>I did a bit more digging to see what the connection is with the power cable and it seems unrelated. The flicker happens only when the power cable is connected AND the power mode is performance (or balanced***see bottom of post***). But, power_dpm_state seems to be ignored unless the power cable is plugged in. To test this I ran unigine-heaven with default settings power cable + battery dpm state = 4fps power cable + performance dpm state = 8fps no power cable + battery dpm state = 4fps no power cable + performance dpm state = 4fps So obviously the last result tells us that having the power cable unplugged forces "battery" mode regardless of whether "performance" is set in power_dpm_state and the power cable itself is a bit of a red herring, it's the performance dpm state which causes the flicker and having the power cable connected is the only way to get the gpu into performance mode. (These numbers seem rather low for a M370X GPU since it apparently gets 35 in windows, see <a href="http://www.mobiletechreview.com/notebooks/15-inch-Retina-MacBook-Pro-2015.htm">http://www.mobiletechreview.com/notebooks/15-inch-Retina-MacBook-Pro-2015.htm</a> I'm not sure how the radeon driver stacks up and I'm not really bothered about that as I don't any gpu intensive work, but the performance may highlight clock speed issues) ***** Note on "balanced". Since "balanced" always seems to cause the flicker and high temperatures when enabled, it suggests that it's being rather over-zealous with its clock speeds. Forcing "battery" has no noticeable impact on performance in desktop applications. I'm not sure how it's measured but "balanced" would probably be better with a different threshold.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>