<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [snb DP-to-DVI dongle] miniDP to external monitor with DVI-D via miniDP to DVI-D adapter and blank screen" href="https://bugs.freedesktop.org/show_bug.cgi?id=106596#c9">Comment # 9</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [snb DP-to-DVI dongle] miniDP to external monitor with DVI-D via miniDP to DVI-D adapter and blank screen" href="https://bugs.freedesktop.org/show_bug.cgi?id=106596">bug 106596</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 genpur from <a href="show_bug.cgi?id=106596#c7">comment #7</a>) > When adapter is disconnected : > LC_MESSAGES=en_UK.UTF-8 sudo dd if=/dev/drm_dp_aux0 bs=1 skip=$((0x200)) > count=1 | od -tx1 > dd: error reading '/dev/drm_dp_aux0': Connection timed out As expected. > When adapter is connected : > LC_MESSAGES=en_UK.UTF-8 sudo dd if=/dev/drm_dp_aux0 bs=1 skip=$((0x200)) > count=1 | od -tx1 > 1+0 records in > 1+0 records out > 1 byte copied, 0.000779381 s, 1.3 kB/s > 0000000 00 That 00 tells us the adapter thinks there are no displays connected to it. That should dynamically change depending on the display being plugged/unplugged into the other end of the cable, and generate a hotplug event. Please double check with a display, and ensure it's on. How about dd if=/dev/drm_dp_aux0 bs=1 skip=$((0x80)) count=16 | od -tx1 Ville, perhaps we should only trust sink count if downstream port is hotplug capable, and assume 1 otherwise? Regardless of what the spec says. See the sink count handling in intel_dp_detect_dpcd() - we never reach that if sink count is 0 in intel_dp_get_dpcd(). Not very consistent.</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>