<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO --- - [gm45 regression] [drm:init_ring_common]: *ERROR* render ring initialization failed" href="https://bugs.freedesktop.org/show_bug.cgi?id=76554#c51">Comment # 51</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO --- - [gm45 regression] [drm:init_ring_common]: *ERROR* render ring initialization failed" href="https://bugs.freedesktop.org/show_bug.cgi?id=76554">bug 76554</a> from <a class="email" href="mailto:jikos@jikos.cz" title="Jiri Kosina <jikos@jikos.cz>"> Jiri Kosina</a> <pre>(In reply to <a href="show_bug.cgi?id=76554#c50">comment #50</a>) I probably wasn't super clear what I was referring to by this comment: > The problematic condition causing the whole ring to be claimed dead is > > I915_READ_HEAD(ring) & HEAD_ADDR) == 8 > > right? > > I915_READ_HEAD(ring) returns 000e200c HEAD_ADDR is 0x001FFFFC, so the result > is e200c, not the expected value of 8, causing the ring initialization > failure. I was referring to this: (In reply to <a href="show_bug.cgi?id=76554#c49">comment #49</a>) > So it passes the immediate check that HEAD is valid after setting CTRL, but > then fails shortly afterwards. Humph. I am not sure what is going on! because I don't see any check for HEAD validity after settin CTRL; I only see I915_READ_START(ring) != i915_gem_obj_ggtt_offset(obj) check, but no I915_READ_HEAD() check ... but obviously, I am absolutely unfamiliar with this code, so sorry for creating unnecessary noise likely. > > I wonder if it is as simple as the combination of reads failing?</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>