<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [SKL dmc] Headless mode media transcoding is 20-30% slower comparing to connected monitor use case" href="https://bugs.freedesktop.org/show_bug.cgi?id=100572#c26">Comment # 26</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [SKL dmc] Headless mode media transcoding is 20-30% slower comparing to connected monitor use case" href="https://bugs.freedesktop.org/show_bug.cgi?id=100572">bug 100572</a> from <a class="email" href="mailto:imre.deak@intel.com" title="Imre Deak <imre.deak@intel.com>"> Imre Deak</a> <pre>(In reply to Tvrtko Ursulin from <a href="show_bug.cgi?id=100572#c25">comment #25</a>) > One of the experiments Animesh asked me to do was to look at the state of > the DC_STATE_EN register at runtime. > > It looked that it had reverted to a value other than what was programmed by > i915. On top of that, it looked impossible to manually modify it at runtime. > > The value it is reverting to was DC_STATE_EN_UPTO_DC6, regardless of whether > the driver has programmed DC_STATE_EN_UPTO_DC5 or DC_STATE_EN_UPTO_DC5 | > DC_STATE_EN_UPTO_DC6. > > This coupled with a comment in gen9_write_dc_state makes me suspicious > whether DMC is not doing things behind the drivers back? We don't use DC5 on SKL normally only DC6. Did you boot with i915.enable_dc set to something non-default?</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are on the CC list for the bug.</li> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>