Bug 90153

Summary: [SKL Bisected]ES3-CTS.gtf.GL3Tests.uniform_buffer_object.uniform_buffer_object_all_valid_basic_types fails
Product: Mesa Reporter: lu hua <huax.lu>
Component: Drivers/DRI/i965Assignee: Neil Roberts <nroberts>
Status: VERIFIED FIXED QA Contact: Intel 3D Bugs Mailing List <intel-3d-bugs>
Severity: normal    
Priority: high CC: idr, james.ausmus
Version: git   
Hardware: All   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments: output
i965/skl: Force the exec size to 8 when initing header for SIMD4x2

Description lu hua 2015-04-23 07:38:09 UTC 
Created attachment 115286 [details]
output

System Environment:
--------------------------
Platform: SKL
Libdrm:		(master)libdrm-2.4.60-34-g0d78b37b1cac304ce5e84d1207f0a43abd29c000
Mesa:		(master)00bf7d2e9cd60dbd82d25b459c448e11c545a89a
Xserver:	(master)xorg-server-1.17.0-76-gb1029716e41e252f149b82124a149da180607c96
Xf86_video_intel:(master)2.99.917-282-g83b8528773a0b1e6655fa87c9645a0062cee1359
Libva:		(master)062a63932c0f1439aa587aa986bbcfb758ff38f2
Libva_intel_driver:(master)890f538f62707ec07a6accdb65bafcaffc941bb1
Kernel:   (drm-intel-nightly)b9fe357740009b89d4bac30b297bfe9808957e6a

Bug detailed description:
-----------------------------
It fails on SNB+ platforms with mesa master branch.

Bisect shows: 07c571a39fa12c3db1c638302de7aed67844609b is the first bad commit.
commit 07c571a39fa12c3db1c638302de7aed67844609b
Author:     Neil Roberts <neil@linux.intel.com>
AuthorDate: Fri Apr 10 17:20:21 2015 +0100
Commit:     Neil Roberts <neil@linux.intel.com>
CommitDate: Tue Apr 14 19:20:28 2015 +0100

    i965/skl: Use an exec size of 8 to initialise the message header

    Commit e93566a15c61c33faa changed the message header code needed to
    make Skylake use SIMD4x2 so that it uses a register with width 4
    instead of 8 as the source register in the send message. However it
    also changed the width for the dest in the MOV instruction which is
    used to initialise the header register with the values from g0. The
    width of the destination is used to determine the exec size in
    brw_set_dest so this would end up making the MOV have an exec size of
    4. I think this would end up leaving the top half of the register
    uninitialised. The top half of the header has meaningful values so
    this probably isn't a good idea.

    This patch just casts the dest register for the MOV instruction back
    to a vec8 to fix it. It doesn't cause any changes to a Piglit run.

    Reviewed-by: Ben Widawsky <ben@bwidawsk.net>

Reproduce steps:
---------------------------- 
1. xinit
2. ./glcts --deqp-case=ES3-CTS.gtf.GL3Tests.uniform_buffer_object.uniform_buffer_object_all_valid_basic_types --deqp-surface-width=64 --deqp-surface-height=64 --deqp-base-seed=1 --deqp-surface-type=window --deqp-gl-config-id=14
Comment 1 lu hua 2015-04-23 07:49:30 UTC 
Following cases also fail with the same bisect commit:
ES3-CTS.gtf.GL3Tests.uniform_buffer_object.uniform_buffer_object_arrays_of_all_valid_basic_types
ES3-CTS.gtf.GL3Tests.uniform_buffer_object.uniform_buffer_object_block_member_layouts
ES3-CTS.gtf.GL3Tests.uniform_buffer_object.uniform_buffer_object_inherit_and_override_layouts
ES3-CTS.gtf.GL3Tests.uniform_buffer_object.uniform_buffer_object_not_whole_uniform_array_active
ES3-CTS.gtf.GL3Tests.uniform_buffer_object.uniform_buffer_object_repeat_global_scope_layouts
ES3-CTS.gtf.GL3Tests.uniform_buffer_object.uniform_buffer_object_storage_layouts
ES3-CTS.gtf.GL3Tests.uniform_buffer_object.uniform_buffer_object_structures_of_all_valid_basic_types
ES3-CTS.gtf.GL3Tests.uniform_buffer_object.uniform_buffer_object_unused_uniforms_in_std140

Many ES3-CTS.shaders.uniform_block*(about 570 cases) cases also fail with this commit.
Comment 2 Neil Roberts 2015-04-23 17:50:52 UTC 
Created attachment 115299 [details] [review]
i965/skl: Force the exec size to 8 when initing header for SIMD4x2

Thanks for the bug report. I don't have access to a Skylake machine to test today but I think I have replicated the problem by temporarily forcing this code path on Haswell.

Would you be able to test with this patch?
Comment 3 lu hua 2015-04-24 04:52:25 UTC 
(In reply to Neil Roberts from comment #2)
> Created attachment 115299 [details] [review] [review]
> i965/skl: Force the exec size to 8 when initing header for SIMD4x2
> 
> Thanks for the bug report. I don't have access to a Skylake machine to test
> today but I think I have replicated the problem by temporarily forcing this
> code path on Haswell.
> 
> Would you be able to test with this patch?

Test full ogles3conform case, Fixed by this patch.
Comment 4 Neil Roberts 2015-05-01 11:09:20 UTC 
I've pushed the patch to master:

http://cgit.freedesktop.org/mesa/mesa/commit/?id=be119e80c9414aaf5101809c4
Comment 5 lu hua 2015-05-05 08:33:30 UTC 
Verified.Fixed.

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