Bug 108641

Summary: Shader causes Interlaced dark lines on R600g in XCOM2
Product: Mesa Reporter: steelwinged
Component: Drivers/Gallium/r600Assignee: Default DRI bug account <dri-devel>
Status: RESOLVED MOVED QA Contact: Default DRI bug account <dri-devel>
Severity: normal    
Priority: medium CC: steelwinged
Version: 19.1   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments: in-game screenshot
Shader suspected of causing defect

Description steelwinged 2018-11-03 12:18:44 UTC
Created attachment 142355 [details]
in-game screenshot

Game engine rendering outputs are interlaced with dark lines on r600.

Tested on: 7660G (Aruba) and 7670M (Turks) with Mesa 18.2.4.
Renderdoc captures have been uploaded here: https://www32.zippyshare.com/v/G74cEAp5/file.html
Comment 1 steelwinged 2018-11-04 11:19:25 UTC
If it's of any help, I have managed to narrow down the first output appearance of these interlacing lines between events glDispatchCompute(80, 45, 1) and second call of glDrawElementsBaseVertex(48).
Comment 2 steelwinged 2018-12-16 15:41:15 UTC
Refreshing the upload due to the link expiring: https://www38.zippyshare.com/v/d0oWhmbR/file.html

Just a remark, the capture was taken with RenderDoc 1.1 and the bug still occurs on Mesa 18.3.1.
Comment 3 steelwinged 2019-08-04 17:06:29 UTC
Situation still occurs on Mesa 19.1.3, refreshed RenderDoc capture at https://www47.zippyshare.com/v/fL6gXv7u/file.html

I might be conflating things, but there's also a shader scheduling error:

##post_scheduler: unscheduled pending instructions :MOV     R27.x.5@R1.w,    R17.x.1@R1.x
MOV     R27.x.3@R1.y,    R17.w.1@R0.z
MOV     R17.x.1@R1.x,    A9.y[R16.x.1@R0.w]_73F@R1.y
                                            rels: A9.y[R16.x.1@R0.w]_73F@R1.y :  <= R9.y.1F, R10.y.1F, R11.y.1F, R12.y.1F, R13.y.1F, R14.y.1F
MOV     R17.w.1@R0.z,    A9.x[R16.x.1@R0.w]_62F@R1.x
                                            rels: A9.x[R16.x.1@R0.w]_62F@R1.x :  <= R9.x.1F, R10.x.1F, R11.x.1F, R12.x.1F, R13.x.1F, R14.x.1F
MOV     R14.y.1F,    4.2039e-45|00000003
MOV     R13.y.1F,    4.2039e-45|00000003
MOV     R12.y.1F,    7.00649e-45|00000005
MOV     R11.y.1F,    5.60519e-45|00000004
MOV     R10.y.1F,    4.2039e-45|00000003
MOV     R9.y.1F,    4.2039e-45|00000003
FLT_TO_UINT     R16.x.1@R0.w,    C4102.x
MOV     R14.x.1F,    1.4013e-45|00000001
MOV     R13.x.1F,    0|00000000
MOV     R12.x.1F,    0|00000000
MOV     R11.x.1F,    0|00000000
MOV     R10.x.1F,    5.60519e-45|00000004
MOV     R9.x.1F,    7.00649e-45|00000005

I don't read mnemonics, but I'm guessing that could be "Shader 9120" from the capture, which also causes the interlacing lines. I'm attaching it shortly.
Comment 4 steelwinged 2019-08-04 17:07:10 UTC
Created attachment 144946 [details]
Shader suspected of causing defect
Comment 5 steelwinged 2019-08-05 19:27:50 UTC
Can confirm that the program with the attached compute shader is producing these lines, compared to nvidia.
Comment 6 GitLab Migration User 2019-09-18 19:26:43 UTC
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/mesa/mesa/issues/648.

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