Bug 107857

Summary: GPU hang - GS_EMIT without shader outputs
Product: Mesa Reporter: Józef Kucia <joseph.kucia>
Component: Drivers/Gallium/radeonsiAssignee: Default DRI bug account <dri-devel>
Status: RESOLVED FIXED QA Contact: Default DRI bug account <dri-devel>
Severity: normal    
Priority: medium    
Version: git   
Hardware: Other   
OS: All   
Whiteboard:
i915 platform: i915 features:
Attachments: apitrace

Description Józef Kucia 2018-09-07 10:51:42 UTC 
Created attachment 141472 [details]
apitrace

This can be reproduced reliably using the attached apitrace.

OpenGL renderer string: Radeon RX Vega (VEGA10, DRM 3.23.0, 4.15.5-gentoo, LLVM 6.0.0)
OpenGL core profile version string: 4.5 (Core Profile) Mesa 18.3.0-devel (git-1c7a2433b2)
Comment 1 Józef Kucia 2018-09-23 22:57:50 UTC 
GS_EMIT without shader outputs seems to cause GPU hangs. Radeonsi generates shaders with GS_EMIT without writing shader outputs when geometry shader outputs are optimized out.

a potential fix: https://lists.freedesktop.org/archives/mesa-dev/2018-September/205848.html
piglit test: https://lists.freedesktop.org/archives/piglit/2018-September/025092.html
Comment 2 Józef Kucia 2018-10-02 21:52:15 UTC 
Fixed by commit e24a4e05c7a7b9f3a06fa55284d6258ceff44fdd
https://cgit.freedesktop.org/mesa/mesa/commit/?id=e24a4e05c7a7b9f3a06fa55284d6258ceff44fdd

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