<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [SKL Xeon DP-to-VGA] no hotplug signal from DP-to-VGA branch device after unplug/replug cycle" href="https://bugs.freedesktop.org/show_bug.cgi?id=101044#c17">Comment # 17</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [SKL Xeon DP-to-VGA] no hotplug signal from DP-to-VGA branch device after unplug/replug cycle" href="https://bugs.freedesktop.org/show_bug.cgi?id=101044">bug 101044</a> from <a class="email" href="mailto:jani.nikula@intel.com" title="Jani Nikula <jani.nikula@intel.com>"> Jani Nikula</a> <pre>(In reply to amy.shih from <a href="show_bug.cgi?id=101044#c13">comment #13</a>) > Could you explain why we need to add this patch to make VGA work & does this > patch have any side effect? Without the patch, we tell the DP sink (or, in this case, the DP branch device, the DP-to-VGA converter) to go to power save mode when we disable it. Apparently the branch device in question doesn't wake up like other devices, and sleeps forever instead of waking up on hotplug. If the logs in <a href="show_bug.cgi?id=101044#c8">comment #8</a> are to be trusted, we really don't get a hotplug event from the branch device anymore, so we won't even try to talk to it to wake it up. The drawback with the patch is that it'll potentially waste power.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> <li>You are on the CC list for the bug.</li> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>