Bug 107728 - Wrong background in Sascha Willem's Multisampling Demo
Summary: Wrong background in Sascha Willem's Multisampling Demo
Status: ASSIGNED
Alias: None
Product: Mesa
Classification: Unclassified
Component: Drivers/Vulkan/intel (show other bugs)
Version: 18.1
Hardware: x86-64 (AMD64) All
: medium normal
Assignee: Rafael Antognolli
QA Contact: Intel 3D Bugs Mailing List
URL:
Whiteboard:
Keywords: bisected, regression
Depends on:
Blocks:
 
Reported: 2018-08-28 16:23 UTC by LunarG
Modified: 2018-12-04 20:10 UTC (History)
2 users (show)

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Description LunarG 2018-08-28 16:23:18 UTC
Introduced in the 18.1 branch (commit 92eb5bbc68d732463e9afb2373c9bd47e5ee0864), running Sascha Willem's Multisampling demo (https://github.com/SaschaWillems/Vulkan) will produce a black background where it should be white. 

Mesa versions from 18.0 produces the correct results. 

[Hardware]
Skylake CPU (530 graphics)

[Software]
Mesa 18.1, Ubuntu 16.04
Using Vkreplay from LunarG's SDK
Comment 1 Rafael Antognolli 2018-08-29 00:01:39 UTC
Quick update on this: in theory we should just revert that patch, because it's wrong, and even if we "fix" it by properly skipping the update of the clear color only during fast clears, we would only be saving a couple MI_MEM_COPY operations. It's probably better to just keep the code simpler and remove that logic.

However, while trying to revert it, I found that it regresses Haswell, so I'm debugging that now.
Comment 2 Jason Ekstrand 2018-08-29 00:58:19 UTC
Ugh... I reviewed that patch.  Now that I look at it in light of this, it's obviously wrong.  We also need inline clear colors for the source of MSAA resolves and maybe some other cases.  Rafael, do you remember why you did this?  Was it just to save some MI commands or did it have some deeper purpose?
Comment 3 Rafael Antognolli 2018-08-29 16:08:26 UTC
I don't remember for sure, but I think it was just to save the MI commands. That's the only thing I can remember now.
Comment 4 rukai 2018-12-04 20:10:26 UTC
Hi,
Looks like we hit this bug: https://github.com/vulkano-rs/vulkano/issues/1123
Has there been any progress?


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