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Added another backwards compatibility fix
This commit is contained in:
Benjamin Höglinger-Stelzer
2020-09-10 16:44:35 +02:00
parent aa47747738
commit 8717bc34ac
1 changed files with 36 additions and 0 deletions
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36
sdk/src/ViGEmClient.cpp
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@@ -445,6 +445,19 @@ VIGEM_ERROR vigem_target_add(PVIGEM_CLIENT vigem, PVIGEM_TARGET target)
plugin.VendorId = target->VendorId;
plugin.ProductId = target->ProductId;
/*
* Request plugin of device. This is an inherently asynchronous operation,
* which is addressed differently through the history of the driver design.
* Pre-v1.17 this request was kept pending until the child was deemed operational
* which unfortunately causes synchronization issues on some systems.
* Starting with v1.17 "waiting" for full power-up is done with an additional
* IOCTL that is sent immediately after and kept pending until the driver
* reports that the device can receive report updates. The following section
* and error handling is designed to achieve transparent backwards compatibility
* to not break applications using the pre-v1.17 client SDK. This is not a 100%
* perfect and can cause other functions to fail if called too soon but
* hopefully the applications will just ignore these errors and retry ;)
*/
DeviceIoControl(
vigem->hBusDevice,
IOCTL_VIGEM_PLUGIN_TARGET,
@@ -456,8 +469,20 @@ VIGEM_ERROR vigem_target_add(PVIGEM_CLIENT vigem, PVIGEM_TARGET target)
&olPlugIn
);
//
// This should return fairly immediately >=v1.17
//
if (GetOverlappedResult(vigem->hBusDevice, &olPlugIn, &transferred, TRUE) != 0)
{
/*
* This function is announced to be blocking/synchronous, a concept that
* doesn't reflect the way the bus driver/PNP manager bring child devices
* to life. Therefore, we send another IOCTL which will be kept pending
* until the bus driver has been notified that the child device has
* reached a state that is deemed operational. This request is only
* supported on drivers v1.17 or higher, so gracefully cause errors
* of this call as a potential success and keep the device plugged in.
*/
VIGEM_WAIT_DEVICE_READY_INIT(&devReady, plugin.SerialNo);
DeviceIoControl(
@@ -479,6 +504,17 @@ VIGEM_ERROR vigem_target_add(PVIGEM_CLIENT vigem, PVIGEM_TARGET target)
break;
}
//
// Backwards compatibility with version pre-1.17, where this IOCTL doesn't exist
//
if (GetLastError() == ERROR_INVALID_PARAMETER)
{
target->State = VIGEM_TARGET_CONNECTED;
error = VIGEM_ERROR_NONE;
break;
}
//
// Don't leave device connected if the wait call failed
//