<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [BAT][SKL] Serial console hung in kms_flip when running IGT" href="https://bugs.freedesktop.org/show_bug.cgi?id=100258#c1">Comment # 1</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [BAT][SKL] Serial console hung in kms_flip when running IGT" href="https://bugs.freedesktop.org/show_bug.cgi?id=100258">bug 100258</a> from <a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> Chris Wilson</a> <pre>Each character has a 1s timeout in wait_for_xmitr. If the string was log enough and the serial console bust, it can easily appear to be hung. As wait_for_xmitr keeps poking the nmi watchdog. the slow loop will not be caught. If that is correct, this appears to be a hw issue. An alternative hypothesis is that the usb device struct sent garbage to be printed and it really is stuck printing out all of memory, 1 character at a time. Kasan might help. I don't think the vtcon switch of modes is significant. What would be useful is the dmesg before to see if we can identify what usb event triggered.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>