<html>
<head>
<base href="https://bugs.freedesktop.org/" />
</head>
<body>
<p>
<div>
<b><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [NV84] Repeated system crashes under graphics load, E[PFIFO] DMA_PUSHER and lots of E[PGRAPH]"
href="https://bugs.freedesktop.org/show_bug.cgi?id=70390#c10">Comment # 10</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [NV84] Repeated system crashes under graphics load, E[PFIFO] DMA_PUSHER and lots of E[PGRAPH]"
href="https://bugs.freedesktop.org/show_bug.cgi?id=70390">bug 70390</a>
from <span class="vcard"><a class="email" href="mailto:Martin.vGagern@gmx.net" title="Martin von Gagern <Martin.vGagern@gmx.net>"> <span class="fn">Martin von Gagern</span></a>
</span></b>
<pre>Created <span class=""><a href="attachment.cgi?id=87553" name="attach_87553" title="report 0x00406040 value in nouveau_bo_wr32">attachment 87553</a> <a href="attachment.cgi?id=87553&action=edit" title="report 0x00406040 value in nouveau_bo_wr32">[details]</a></span> <a href='page.cgi?id=splinter.html&bug=70390&attachment=87553'>[review]</a>
report 0x00406040 value in nouveau_bo_wr32
(In reply to <a href="show_bug.cgi?id=70390#c9">comment #9</a>)
<span class="quote">> (In reply to <a href="show_bug.cgi?id=70390#c8">comment #8</a>)
> > So... the mystery is where does this 0x40 method come from.
>
> Can we add a bit of debug code somewhere, to detect that specific value when
> it enters the ring, and emit useful information like a kernel stack trace?</span >
Gave this a stab, using a BUG_ON conditional the way this attachment describes
it. Unless static function scope variables don't work the same in kernel space
and in unser space, this should report if, BEGIN_NV04, OUT_RING or some other
command was used to write this value.
Result: I managed to get that first DMA_PUSHER line all by itself:
nouveau E[ PFIFO][0000:01:00.0] DMA_PUSHER - ch 4 [stellarium[14333]] get
0x0020111a6c put 0x0020116e10 ib_get 0x00000070 ib_put 0x00000097 state
0x80007641 (err: INVALID_CMD) push 0x00406040
With no stack trace or other indication that my BUG_ON got triggered. Also with
no subsequent error messages, or system crash.
So I'd conclude that the line does not neccessarily lead to a crash, and that
the critical value does not get written via nouveau_bo_wr32. Where else could
it come from? What is the most central location where I might put such code?</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the assignee for the bug.</li>
</ul>
</body>
</html>