<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - Screen is frozen on second connection of DP MST dock" href="https://bugs.freedesktop.org/show_bug.cgi?id=107546#c46">Comment # 46</a> on <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - Screen is frozen on second connection of DP MST dock" href="https://bugs.freedesktop.org/show_bug.cgi?id=107546">bug 107546</a> from <a class="email" href="mailto:stanislav.lisovskiy@intel.com" title="Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>"> Stanislav Lisovskiy</a> <pre>(In reply to Brian Ward from <a href="show_bug.cgi?id=107546#c45">comment #45</a>) > (In reply to Stanislav Lisovskiy from <a href="show_bug.cgi?id=107546#c44">comment #44</a>) > > Hi, > > > > I guess you need to apply this patch: > > > > <a href="https://patchwork.freedesktop.org/patch/261135/">https://patchwork.freedesktop.org/patch/261135/</a> > > Thanks for the suggestion Stan, unfortunately that one didn't change any > behavior for me, and it appears it is already committed to the 4.19 branch. > > I've tested with a custom build direct from 4.19 as well as custom fedora > build from 4.19, and latest fedora release 4.19.13-300.fc29.x86_64, all of > which appear to already have that patch. > > Looks like there are a lot of big changes in the two files that seem most > likely culprits to the errors... > > $ git diff v4.20 v4.19 -- drivers/gpu/drm/i915/intel_dp_link_training.c | > grep @@ | wc -l > 5 > $ git diff v4.20 v4.19 -- drivers/gpu/drm/i915/intel_ddi.c | grep @@ | wc -l > 16 > > I'll try to find some time to actually debug the error on v4.19 and find out > what changes resolve the problem, but it may be a while. Do you get a similar call trace? > [ 321.497722] Call Trace: > [ 321.497725] refcount_inc+0x5/0x30 > [ 321.497730] drm_dp_get_mst_branch_device+0xc2/0xe0 [drm_kms_helper] > [ 321.497735] drm_dp_mst_hpd_irq+0x104/0x8c0 [drm_kms_helper] > [ 321.497750] ? intel_dp_check_mst_status+0xba/0x1e0 [i915] > [ 321.497763] intel_dp_check_mst_status+0xba/0x1e0 [i915] > [ 321.497776] intel_dp_hpd_pulse+0x176/0x2e0 [i915] > [ 321.497778] ? __switch_to_asm+0x40/0x70 > [ 321.497791] i915_digport_work_func+0x8f/0x120 [i915] > [ 321.497794] process_one_work+0x195/0x370 > [ 321.497795] worker_thread+0x30/0x390 > [ 321.497797] ? process_one_work+0x370/0x370 > [ 321.497799] kthread+0x113/0x130 > [ 321.497800] ? kthread_create_worker_on_cpu+0x70/0x70 > [ 321.497802] ret_from_fork+0x35/0x40 <a href="https://patchwork.freedesktop.org/patch/261135/">https://patchwork.freedesktop.org/patch/261135/</a> patch reportedly fixes the issue in <a class="bz_bug_link bz_status_CLOSED bz_closed" title="CLOSED FIXED - USB-C dock unplug trigger NULL pointer access" href="show_bug.cgi?id=108616">https://bugs.freedesktop.org/show_bug.cgi?id=108616</a>, which has exactly same backtrace. Otherwise I have a feeling that we are talking about different issues in a same ticket here.</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>