app_server: turn DPMS on only after setting a valid mode

It's not allowed to enable the screen before having set a mode. At least
in the case of the intel_extreme driver, this creates some problem. Move
the call just a bit later in the init process, where the mode is already
set.

Change-Id: Iaa665f0edc15316890032f1a5928f33634dc8749
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4362
Reviewed-by: Adrien Destugues <[email protected]>
Reviewed-by: François Revol <[email protected]>
Reviewed-by: <[email protected]>

src/servers/app/Desktop.cpp

@@ -519,6 +519,8 @@ Desktop::Init()
 		return B_ERROR;
 	}
 
+	HWInterface()->SetDPMSMode(B_DPMS_ON);
+
 	float brightness = fWorkspaces[0].StoredScreenConfiguration().Brightness(0);
 	if (brightness > 0)
 		HWInterface()->SetBrightness(brightness);

src/servers/app/Screen.cpp

@@ -74,11 +74,6 @@ Screen::Initialize()
 		status = fHWInterface->Initialize();
 	}
 
-	// Turn on screen if this is not yet done by BIOS
-	if (status == B_OK)
-		fHWInterface->SetDPMSMode(B_DPMS_ON);
-
-
 	return status;
 }
 

src/servers/app/VirtualScreen.cpp

@@ -124,8 +124,11 @@ VirtualScreen::AddScreen(Screen* screen, ScreenConfigurations& configurations)
 		// we found settings for this screen, and try to apply them now
 		status = screen->SetMode(mode);
 	}
+
 	if (status != B_OK) {
-		status_t status = screen->SetPreferredMode();
+		// We found no configuration or it wasn't valid, try to fallback to
+		// sane values
+		status = screen->SetPreferredMode();
 		if (status != B_OK)
 			status = screen->SetBestMode(1024, 768, B_RGB32, 60.f);
 		if (status != B_OK)
@@ -133,6 +136,9 @@ VirtualScreen::AddScreen(Screen* screen, ScreenConfigurations& configurations)
 		if (status != B_OK) {
 			debug_printf("app_server: Failed to set mode: %s\n",
 				strerror(status));
+
+			delete item;
+			return status;
 		}
 	}