1820066 - Fix some DXGI-related D3D11 debug-layer warnings when using swapchains

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Ray Kraesig [:rkraesig]]

When enabling the D3D11 debug layer and running without DirectComposition, an easily-fixed DXGI warning and error appear in the debug output:

[18532] DXGI WARNING: IDXGIFactory::CreateSwapChain: Blt-model swap effects (DXGI_SWAP_EFFECT_DISCARD and DXGI_SWAP_EFFECT_SEQUENTIAL) are legacy swap effects that are predominantly superceded by their flip-model counterparts (DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL and DXGI_SWAP_EFFECT_FLIP_DISCARD). Please consider updating your application to leverage flip-model swap effects to benefit from modern presentation enhancements. More information is available at http://aka.ms/dxgiflipmodel. [ MISCELLANEOUS WARNING #294: ]

[18532] DXGI ERROR: IDXGIFactory::CreateSwapChain: Blt model swapchains (DXGI_SWAP_EFFECT_SEQUENTIAL and DXGI_SWAP_EFFECT_DISCARD) do not support DXGI_SCALING_NONE. [function arguments omitted] [ MISCELLANEOUS ERROR #141: ]

These are relatively easy to address, and doing so has other salutary effects -- in particular, suppressing bug 1763981.

Comment 1

[Ray Kraesig [:rkraesig]]

Attachment: Bug 1820066 [1/3] - Fix `CreateSwapChainForHwnd` call r?sotaro

Per Microsoft documentation, DXGI_SCALING_NONE is only supported by
swap chains using DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL; for any other swap
effect, including DXGI_SWAP_EFFECT_SEQUENTIAL, another value must be
supplied. Prior to Windows 10 the only such available entry was
DXGI_SCALING_STRETCH, so use that.

This causes the CreateSwapChainForHwnd call to succeed, rather than
causing us to fall back to CreateSwapChain. There is no known user-
facing effect here, as DXGI_SCALING_STRETCH is documented to be the
semantics applied by CreateSwapChain -- but it does eliminate an error
message from the D3D11 debug layer's output.

Comment 2

[Ray Kraesig [:rkraesig]]

Attachment: Bug 1820066 [3/3] - Default to DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL on Win10+ r?sotaro

This silences a warning emitted by the D3D11 debug layer.

Conveniently, it also suppresses bug 1763981.

Depends on D171521

Comment 3

[Ray Kraesig [:rkraesig]]

N.B.: Bug 1435995 was previously filed concerning swapchains with DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL causing the fallback in-process compositor not to work. I can no longer reproduce this on my local build (with WebRender DirectComposition disabled).

This appears to be dealt with by bug 1567347: when gfx.webrender.flip-sequential is set to true, a separate compositor window (like that used with DirectComposition) is created. The DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL swapchain is associated with the compositor HWND instead of the parent-process HWND, so there's no issue when falling back to the parent process.

Comment 4

[Ray Kraesig [:rkraesig]]

Attachment: Bug 1820066 [2/3] - Allow in-process use of the compositor window r?sotaro

The in-process compositor assumes that no compositor window was present.
This is not guaranteed to be true if, for example, the preference
gfx.webrender.flip-sequential is set.

Make the in-process compositor more closely mirror the out-of-process
compositor. (At present this effectively just means calling ::SetParent
on the compositor window.)

Depends on D171521

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:gw, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c34dfd018abb
[1/3] - Fix `CreateSwapChainForHwnd` call  r=sotaro
https://hg.mozilla.org/integration/autoland/rev/ec623d25b138
[2/3] - Allow in-process use of the compositor window  r=sotaro
https://hg.mozilla.org/integration/autoland/rev/501d93d8c9eb
[3/3] - Default to DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL on Win10+  r=sotaro

Comment 7

[Sandor Molnar[:smolnar]]

Backed out for causing xpc failures in widget/headless/tests/test_headless.js

Backout link: https://hg.mozilla.org/integration/autoland/rev/2e7828044675351f72c755a059c1530b71455c21

Push with failures

Failure log -> PROCESS-CRASH | widget/headless/tests/test_headless.js | application crashed [@ mozilla::layers::CompositorBridgeParent::InitSameProcess]

Comment 8

[Ray Kraesig [:rkraesig]]

It's a relatively simple fix to handle headless mode properly; but it's still worth requesting rereview before landing, I think.

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c8742f6c466f
[1/3] - Fix `CreateSwapChainForHwnd` call  r=sotaro
https://hg.mozilla.org/integration/autoland/rev/062f325dfd28
[2/3] - Allow in-process use of the compositor window  r=sotaro
https://hg.mozilla.org/integration/autoland/rev/ec948153333a
[3/3] - Default to DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL on Win10+  r=sotaro

Comment 10

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/c8742f6c466f
https://hg.mozilla.org/mozilla-central/rev/062f325dfd28
https://hg.mozilla.org/mozilla-central/rev/ec948153333a

Comment 11

[Ray Kraesig [:rkraesig]]

Partially reverted in bug 1830792.