<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - ThinkPad T450 - Broadwell-U: [drm:intel_dp_start_link_train [i915]] *ERROR* failed to enable link training" href="https://bugs.freedesktop.org/show_bug.cgi?id=108687#c9">Comment # 9</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - ThinkPad T450 - Broadwell-U: [drm:intel_dp_start_link_train [i915]] *ERROR* failed to enable link training" href="https://bugs.freedesktop.org/show_bug.cgi?id=108687">bug 108687</a> from <a class="email" href="mailto:ville.syrjala@linux.intel.com" title="Ville Syrjala <ville.syrjala@linux.intel.com>"> Ville Syrjala</a> <pre>(In reply to Diego Viola from <a href="show_bug.cgi?id=108687#c8">comment #8</a>) > Created <a href="attachment.cgi?id=142414" name="attach_142414" title="dmesg w/ drm.debug=0xe exhibiting the error (no xrandr)">attachment 142414</a> <a href="attachment.cgi?id=142414&action=edit" title="dmesg w/ drm.debug=0xe exhibiting the error (no xrandr)">[details]</a> > dmesg w/ drm.debug=0xe exhibiting the error (no xrandr) > > I've ran another dmesg capture with drm.debug=0xe and got another error: > > [22701.493597] [drm:intel_dp_start_link_train [i915]] *ERROR* failed to get > link status > [22701.493635] [drm:intel_dp_start_link_train [i915]] [CONNECTOR:72:DP-1] > Link Training failed at link rate = 162000, lane count = 4 > > I didn't change modes with xrandr at all this time, nor turned off the > monitor manually. > > I've had the screen turn off by default (power saving) a few times though. Is that done by the xserver dpms? First we turn off the crtcs (dpms off perhaps?): [19310.376450] [drm:intel_disable_pipe [i915]] disabling pipe A [19310.434354] [drm:intel_disable_pipe [i915]] disabling pipe B A while later the external display disappears: [22700.475730] [drm:i915_hotplug_work_func [i915]] Connector DP-1 (pin 5) received hotplug event. [22700.475804] [drm:intel_dp_detect [i915]] [CONNECTOR:72:DP-1] [22700.475883] [drm:intel_encoder_hotplug [i915]] [CONNECTOR:72:DP-1] status updated from connected to disconnected Then we try to turn on the crtcs (dpms on?): [22701.493597] [drm:intel_dp_start_link_train [i915]] *ERROR* failed to get link status [22701.493635] [drm:intel_dp_start_link_train [i915]] [CONNECTOR:72:DP-1] Link Training failed at link rate = 162000, lane count = 4 [22701.493697] [drm:intel_dp_modeset_retry_work_fn [i915]] [CONNECTOR:72:DP-1] [22701.494234] [drm:intel_enable_pipe [i915]] enabling pipe B And later the external [22702.090350] [drm:ibx_hpd_irq_handler [i915]] hotplug event received, stat 0x00200000, dig 0x10101012, pins 0x00000020 [22702.090423] [drm:intel_hpd_irq_handler [i915]] digital hpd port B - long [22702.090494] [drm:intel_hpd_irq_handler [i915]] Received HPD interrupt on PIN 5 - cnt: 0 [22702.090583] [drm:intel_dp_hpd_pulse [i915]] got hpd irq on port B - long [22702.090661] [drm:i915_hotplug_work_func [i915]] running encoder hotplug functions [22702.090732] [drm:i915_hotplug_work_func [i915]] Connector DP-1 (pin 5) received hotplug event. And we then succesfully retrain the link: [22702.105236] [drm:intel_dp_start_link_train [i915]] [CONNECTOR:72:DP-1] Link Training Passed at Link Rate = 162000, Lane count = 4 So looks pretty much as expected I suppose. The only slight mystery is who tried to enable the crtc when the display wasn't around. But I suppose that could just be the xserver dpms thing.</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>