<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - Kernel panic when waking up after screens go to dpms sleep" href="https://bugs.freedesktop.org/show_bug.cgi?id=111659#c5">Comment # 5</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - Kernel panic when waking up after screens go to dpms sleep" href="https://bugs.freedesktop.org/show_bug.cgi?id=111659">bug 111659</a> from <a class="email" href="mailto:brad@fnarfbargle.com" title="Brad Campbell <brad@fnarfbargle.com>"> Brad Campbell</a> <pre>I was stating to suspect this might be a hardware problem, so I sourced a similar machine with a Radeon 6770M. Unfortunately the same fault exhibits. [ 2060.703207] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: radeon_dp_needs_link_train+0x69/0x70 [radeon] [ 2060.703221] CPU: 2 PID: 1386 Comm: kworker/2:2 Not tainted 5.3.4+ #19 [ 2060.703223] Hardware name: Apple Inc. iMac12,2/Mac-942B59F58194171B, BIOS 82.0.0.0.0 09/25/2018 [ 2060.703238] Workqueue: events radeon_dp_work_func [radeon] [ 2060.703241] Call Trace: [ 2060.703248] dump_stack+0x46/0x5b [ 2060.703253] panic+0xf3/0x288 [ 2060.703274] ? radeon_dp_needs_link_train+0x69/0x70 [radeon] [ 2060.703278] __stack_chk_fail+0x10/0x10 [ 2060.703294] radeon_dp_needs_link_train+0x69/0x70 [radeon] [ 2060.703308] radeon_connector_hotplug+0xa4/0xd0 [radeon] [ 2060.703323] radeon_dp_work_func+0x28/0x40 [radeon] [ 2060.703326] process_one_work+0x1b4/0x330 [ 2060.703329] worker_thread+0x44/0x3d0 [ 2060.703333] kthread+0xeb/0x120 [ 2060.703336] ? process_one_work+0x330/0x330 [ 2060.703338] ? kthread_park+0xa0/0xa0 [ 2060.703344] ret_from_fork+0x1f/0x30 [ 2060.703382] Kernel Offset: disabled [ 2060.703385] ---[ end Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: radeon_dp_needs_link_train+0x69/0x70 [radeon] ]--- I'm now at a bit of a loss as to how to debug it. I can reproduce it reliably by playing a 1080p video on each head with mplayer and triggering the OSD (volume/brightness) changes. I can't bisect it with an earlier kernel because it doesn't occur when using the internal panel, one Thunderbolt and one HDMI, and the dual thunderbolt support only turned up in 5.2.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>