<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [CI][HSW] Unclaimed read from register 0x70008" href="https://bugs.freedesktop.org/show_bug.cgi?id=102249#c1">Comment # 1</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [CI][HSW] Unclaimed read from register 0x70008" href="https://bugs.freedesktop.org/show_bug.cgi?id=102249">bug 102249</a> from <a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> Chris Wilson</a> <pre>Daniel suggested this might be related to commit 4055dc75d6b51c23602b11c6f716e59b8947ffbf Author: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>> Date: Thu Aug 17 18:32:29 2017 +0100 drm/i915: Stop touching forcewake following a gen6+ engine reset Forcewake is not affected by the engine reset on gen6+. Indeed the reason why we added intel_uncore_forcewake_reset() to gen6_reset_engines() was to keep the bookkeeping intact because the reset did not touch the forcewake bit (yet we cancelled the forcewake consumers)! This was done in commit 521198a2e7095: Author: Mika Kuoppala <<a href="mailto:mika.kuoppala@linux.intel.com">mika.kuoppala@linux.intel.com</a>> Date: Fri Aug 23 16:52:30 2013 +0300 drm/i915: sanitize forcewake registers on reset In reset we try to restore the forcewake state to pre reset state, using forcewake_count. The reset doesn't seem to clear the forcewake bits so we get warn on forcewake ack register not clearing. That futzing of the forcewake bookkeeping was dropped in commit 0294ae7b44bb ("drm/i915: Consolidate forcewake resetting to a single function"), but it did not make the realisation that the remaining intel_uncore_forcewake_reset() was redundant. The new danger with using intel_uncore_forcewake_reset() with per-engine resets is that the driver and hw are still in an active state as we perform the reset. We may be using the forcewake to read protected registers elsewhere and those results may be clobbered by the concurrent dropping of forcewake. but I was not convinced. On the off chance I was wrong...</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>