From 427172edcfb16b10a6609391beb491c661868da5 Mon Sep 17 00:00:00 2001
From: myT <mighty.cow@mailinator.com>
Date: Tue, 7 Jul 2020 09:07:53 +0200
Subject: [PATCH] fixed D3D11 device resets being sometimes treated as fatal
 errors

after getting DXGI_ERROR_DEVICE_REMOVED or D3DDDIERR_DEVICEREMOVED,
GetDeviceRemovedReason can return DXGI_ERROR_DEVICE_RESET
this particular case should trigger a video restart instead of a fatal error
---
 changelog.txt                      |  2 ++
 code/renderer/tr_backend_d3d11.cpp | 35 ++++++++++++++++++++++++++----
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/changelog.txt b/changelog.txt
index 35d673f..4f4ebfb 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -9,6 +9,8 @@ add: r_alphaToCoverageMipBoost <0.0 to 0.5> (default: 0.125) boosts the alpha va
 
 chg: with r_backend GL3, alpha to coverage now requires GLSL 4.00 at a minimum
 
+fix: with r_backend D3D11, some device reset scenarios caused fatal errors instead of video restarts
+
 fix: CVar slots that have been freed (e.g. through unset/cvar_trim/cvar_reset) can now be re-used
 
 fix: with alpha to coverage enabled, high r_picmip values should longer cause
diff --git a/code/renderer/tr_backend_d3d11.cpp b/code/renderer/tr_backend_d3d11.cpp
index 11969a3..7a53c53 100644
--- a/code/renderer/tr_backend_d3d11.cpp
+++ b/code/renderer/tr_backend_d3d11.cpp
@@ -542,16 +542,17 @@ static qbool D3D11_CreateInputLayout(const D3D11_INPUT_ELEMENT_DESC* pInputEleme
 	return CheckAndName(hr, "CreateInputLayout", *ppInputLayout, name);
 }
 
-static const char* GetDeviceRemovedReason()
+static const char* GetDeviceRemovedReasonString(HRESULT reason)
 {
-	switch(d3ds.device->GetDeviceRemovedReason())
+	switch(reason)
 	{
 		case DXGI_ERROR_DEVICE_HUNG: return "device hung";
 		case DXGI_ERROR_DEVICE_REMOVED: return "device removed";
 		case DXGI_ERROR_DEVICE_RESET: return "device reset";
 		case DXGI_ERROR_DRIVER_INTERNAL_ERROR: return "internal driver error";
 		case DXGI_ERROR_INVALID_CALL: return "invalid call";
-		default: return "unknown";
+		case S_OK: return "no error";
+		default: return va("unknown error code 0x%08X", (unsigned int)reason);
 	}
 }
 
@@ -2090,11 +2091,37 @@ static void GAL_EndFrame()
 
 	const UINT presentFlags = d3ds.flipAndTear && r_swapInterval->integer == 0 ? DXGI_PRESENT_ALLOW_TEARING : 0;
 	const HRESULT hr = d3ds.swapChain->Present(abs(r_swapInterval->integer), presentFlags);
+
+	enum PresentError
+	{
+		PE_NONE,
+		PE_DEVICE_REMOVED,
+		PE_DEVICE_RESET
+	};
+	PresentError presentError = PE_NONE;
+	HRESULT deviceRemovedReason = S_OK;
 	if(hr == DXGI_ERROR_DEVICE_REMOVED || hr == D3DDDIERR_DEVICEREMOVED)
 	{
-		ri.Error(ERR_FATAL, "Direct3D device was removed! Reason: %s", GetDeviceRemovedReason());
+		deviceRemovedReason = d3ds.device->GetDeviceRemovedReason();
+		if(deviceRemovedReason == DXGI_ERROR_DEVICE_RESET)
+		{
+			presentError = PE_DEVICE_RESET;
+		}
+		else
+		{
+			presentError = PE_DEVICE_REMOVED;
+		}
 	}
 	else if(hr == DXGI_ERROR_DEVICE_RESET)
+	{
+		presentError = PE_DEVICE_RESET;
+	}
+
+	if(presentError == PE_DEVICE_REMOVED)
+	{
+		ri.Error(ERR_FATAL, "Direct3D device was removed! Reason: %s", GetDeviceRemovedReasonString(deviceRemovedReason));
+	}
+	else if(presentError == PE_DEVICE_RESET)
 	{
 		ri.Printf(PRINT_ERROR, "Direct3D device was reset! Restarting the video system...");
 		Cmd_ExecuteString("vid_restart;");