<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - 4k MST monitor doesn't come back from "xset dpms force off": failed link training" href="https://bugs.freedesktop.org/show_bug.cgi?id=89453#c11">Comment # 11</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - 4k MST monitor doesn't come back from "xset dpms force off": failed link training" href="https://bugs.freedesktop.org/show_bug.cgi?id=89453">bug 89453</a> from <a class="email" href="mailto:palmer@dabbelt.com" title="Palmer Dabbelt <palmer@dabbelt.com>"> Palmer Dabbelt</a> <pre>This bug still exists on linux-4.1.5. I can get my monitor to function correctly if I apply the following patch, but I get some warnings from the kernel during both boot and hotplug. I don't understand how DP hotplug works on my other systems if this intel_dp_hot_plug is empty. Additionally, I went and printk()ed some stuff, and I never seem to have is_mst set. If I understand correctly, this means that I don't have an MST monitor. Should I change this bug's feature to "display/DP"? diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index d714a4b5711e..274bd293d9e9 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -4625,7 +4625,9 @@ static const struct drm_encoder_funcs intel_dp_enc_funcs = { void intel_dp_hot_plug(struct intel_encoder *intel_encoder) { - return; + struct intel_dp *intel_dp = enc_to_intel_dp(&intel_encoder->base); + + intel_dp_check_link_status(intel_dp); } enum irqreturn [ 4.932814] ------------[ cut here ]------------ [ 4.935170] WARNING: CPU: 2 PID: 1180 at drivers/gpu/drm/i915/intel_dp.c:4032 intel_dp_check_link_status+0x16a/0x1b0() [ 4.937557] WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)) [ 4.937589] Modules linked in: [ 4.942308] CPU: 2 PID: 1180 Comm: kworker/2:2 Not tainted 4.1.5+ #12 [ 4.944700] Hardware name: Apple Inc. MacBookPro11,2/Mac-3CBD00234E554E41, BIOS MBP112.88Z.0138.B07.1402121134 02/12/2014 [ 4.947142] Workqueue: events i915_hotplug_work_func [ 4.949583] ffffffff81e86920 ffff88046bbcfca8 ffffffff81a1ea6d 000000000000005a [ 4.952053] ffff88046bbcfcf8 ffff88046bbcfce8 ffffffff810ca965 ffff88046bbcfd08 [ 4.954521] ffff88046caf20e0 ffff88046c9fbb28 0000000000000001 ffff88046b487508 [ 4.956989] Call Trace: [ 4.959445] [<ffffffff81a1ea6d>] dump_stack+0x45/0x57 [ 4.961915] [<ffffffff810ca965>] warn_slowpath_common+0x85/0xc0 [ 4.964389] [<ffffffff810ca9e1>] warn_slowpath_fmt+0x41/0x50 [ 4.966860] [<ffffffff815dc70a>] intel_dp_check_link_status+0x16a/0x1b0 [ 4.969342] [<ffffffff810fc116>] ? pick_next_task_fair+0x206/0x8b0 [ 4.971802] [<ffffffff815dc760>] intel_dp_hot_plug+0x10/0x20 [ 4.974251] [<ffffffff815d21a5>] intel_ddi_hot_plug+0x25/0x30 [ 4.976703] [<ffffffff81586576>] i915_hotplug_work_func+0x1c6/0x2e0 [ 4.979162] [<ffffffff810e0af7>] process_one_work+0x147/0x3f0 [ 4.981626] [<ffffffff810e0eb9>] worker_thread+0x119/0x450 [ 4.984096] [<ffffffff810e0da0>] ? process_one_work+0x3f0/0x3f0 [ 4.986574] [<ffffffff810e5da4>] kthread+0xc4/0xe0 [ 4.989053] [<ffffffff810e5ce0>] ? kthread_create_on_node+0x180/0x180 [ 4.991541] [<ffffffff81a27f92>] ret_from_fork+0x42/0x70 [ 4.994017] [<ffffffff810e5ce0>] ? kthread_create_on_node+0x180/0x180 [ 4.996552] ---[ end trace 2223e668b1c35f11 ]---</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> <li>You are the assignee for the bug.</li> </ul> </body> </html>