<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [SKL Bisected] eDP can not be lighted up after entering kernel" href="https://bugs.freedesktop.org/show_bug.cgi?id=89554#c19">Comment # 19</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [SKL Bisected] eDP can not be lighted up after entering kernel" href="https://bugs.freedesktop.org/show_bug.cgi?id=89554">bug 89554</a> from <a class="email" href="mailto:wendy.wang@intel.com" title="wendy.wang@intel.com">wendy.wang@intel.com</a> <pre>(In reply to Sonika from <a href="show_bug.cgi?id=89554#c9">comment #9</a>) > (In reply to ye.tian from <a href="show_bug.cgi?id=89554#c6">comment #6</a>) > > (In reply to Sonika from <a href="show_bug.cgi?id=89554#c2">comment #2</a>) > > > For me with kernel version 4.0.0-rc3, eDP is working fine. > > > > > > The EDP low vswing table gets selected only when edp_vswing_preemph is set > > > in vbt. > > > For me, it works with both low vswing table as well as the dp translation > > > table with an edp1.3 panel. > > > > > > Only thing I can suspect is that we are trying to use low vswing table for > > > some panel which is not able to handle those values. > > > Can you please see if this variable is set in vbt? > > > If it is set, please try to disable it and try. > > > > I have no idea, could you tell me how to set this variable? where? > > There should be one field in the eDP config in vbt VswingPreEmphasisValue. > Where it should be set to 0 for low vswing and 1 for default for the panel > in use: > 0 = Low Power Swing setting(200 mV) > 1 = Default Swing settings(400 mV) > > If you have access to the code, you can try hardcoding > dev_priv->vbt.edp_low_vswing to false in parse_edp inside intel_bios.c to > use the default vswing values Hello, we read GOP driver's vbt info: pre-emphasis was set to level-0 by default, Voltage Swing was set to swing-0 by default. Both the machines which installed older and newer panels flashed the same GOP driver version.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>