Bug 104731

Summary:	UVD lockup on MPEG2 missing Field
Product:	DRI	Reporter:	Francois Cartegnie <bugzilla77>
Component:	DRM/Radeon	Assignee:	Default DRI bug account <dri-devel>
Status:	RESOLVED NOTABUG	QA Contact:
Severity:	normal
Priority:	medium
Version:	XOrg git
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:

Description Francois Cartegnie 2018-01-22 17:15:44 UTC

We have some broken MPEG2 samples causing lockup in UVD (not only, and also crashing some libs).

At least happens with Radeon 6450 / UVD 3.

Content and not properly packetize and causes video players to send samples containing reference to a missing previous iframe field.

Sample:
https://streams.videolan.org/streams/ts/mpeg2-field-encoded-bff.ts

Our own tracking of this issue
https://trac.videolan.org/vlc/ticket/18916

Comment 1 Andy Furniss 2018-01-22 18:12:33 UTC

FWIW UVD has never (AFAIK) been able to decode field coded mpeg2, as it seems to be quite rare in the wild it doesn't come up much.

A long time ago I managed to lock older h/w with a normal compliance sample.

With my current h/w (tonga) I can't lock with this sample or the compliance - neither decode properly of course, so maybe luck involved in avoiding the lock.

Comment 2 Christian König 2018-01-22 18:26:30 UTC

Works as designed.

On older hardware generations the UVD firmware just stops all processing when it finds an invalid stream.

The driver is then responsible to reset the UVD block with a specific reset procedure to get it working again.

Unfortunately this reset procedure never made it through IP review and so wasn't released to the public.

The only other option is a full ASIC reset which is implemented, but doesn't works so well.

Comment 3 Francois Cartegnie 2018-01-22 19:02:48 UTC

What do you mean by stopping ? 
Ring N lockup kernel messages ?

Comment 4 Christian König 2018-01-22 19:16:24 UTC

(In reply to Francois Cartegnie from comment #3)
> What do you mean by stopping ? 
> Ring N lockup kernel messages ?

Yes, exactly.

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