[Bug 111395] GPU HANG: ecode 9:0:0x86dfbff9, in Map-GL [6016], reason: Hang on render ring, action: reset

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=111395

--- Comment #7 from Kenneth Graunke <kenneth at whitecape.org> ---
A couple quick observations...

1. 3DSTATE_DRAWING_RECTANGLE is usually not the culprit, it's just a
non-pipelined command, which causes the command streamer to stop there until
previous draws complete.  Those previous draws are likely what's actually
hanging.

2. With the updated decode, you can see that the draw immediately before ACTHD
is an indexed trilist draw with 66 vertices.  Prior to that appears to be a
BLORP stencil clear...(?)

3. The beginning of the batch looks somewhat...overwritten with zeroes.

It begins with:

- 6 MI_NOOPs aka DWords of 0
- PIPE_CONTROL <Constant, Texture>
- PIPE_CONTROL <Depth, Render, CS stall>
- STATE_BASE_ADDRESS

We never begin a batch with zeroes, so seeing MI_NOOP (0) is suspect.  In many
cases, that has meant something has written past the end of a buffer and
happens to have clobbered adjacent memory, in this case the batch buffer.

The first draw in the batch is a RECTLIST, so we can assume the first operation
came from BLORP.

The first thing it does is flush caches, which would perform two PIPE_CONTROLs
- the first with <Depth, Render, and CS stall>, then another with <Constant,
Texture>.  PIPE_CONTROL is 6 DWords long, so it's as if the first one got
zeroed out somehow, then the second one is there.  (Then again, at the start of
a new batch, we shouldn't need to do these cache flushes either...)

After that, it emits state base address.  That does a PIPE_CONTROL with <Depth,
DC, Render, CS Stall, Write Immediate>, then SBA, then a PIPE_CONTROL with
<State, Texture, Instruction>.  Those are all present.  After that things look
pretty normal again.

I would suspect a buffer underallocation, but that's just an initial guess...

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-3d-bugs/attachments/20190816/10c68627/attachment-0001.html>