public static Task <T> PerformControlTransferWithRetry <T>(
this IUsbDevice usbDevice,
Func <IUsbDevice, Task <T> > func,
int retryCount = 3,
int sleepDurationMilliseconds = 250)
{
var retryPolicy = Policy
.Handle <ApiException>()
.Or <ControlTransferException>()
.WaitAndRetryAsync(
retryCount,
i => TimeSpan.FromMilliseconds(sleepDurationMilliseconds),
onRetryAsync: (e, t) => usbDevice.ClearStatusAsync()
);
return(retryPolicy.ExecuteAsync(() => func(usbDevice)));
}
public static async Task PerformStmDfTest(IUsbDevice stmDfuDevice)
{
////////////////////////////////////////////////////////////
// required to perform a DFU Clear Status request beforehand
await stmDfuDevice.ClearStatusAsync();
// this sequence aims to test the "send data to device" using the Control Transfer
// executes a DFU "Set Address Pointer" command through the DFU DNLOAD request
////////////////////////////////////
// 1st step: send DFU_DNLOAD request
var dfuRequestResult = await stmDfuDevice.PerformControlTransferWithRetry(ud => ud.SendDownloadRequestAsync());
// Assert that the bytes transfered match the buffer lenght
Assert.IsTrue(dfuRequestResult.BytesTransferred == StmDfuExtensions.DownloadRequestLength);
///////////////////////////////////////
// 2nd step: send DFU_GETSTATUS request
dfuRequestResult = await stmDfuDevice.PerformControlTransferWithRetry(ud => ud.GetStatusAsync());
// Assert that the received buffer has the requested lenght
Assert.IsTrue(dfuRequestResult.BytesTransferred == StmDfuExtensions.GetStatusPacketLength);
// check DFU status
Assert.IsTrue(dfuRequestResult.Data[4] != STATE_DFU_IDLE);
///////////////////////////////////////////////////////////////
// 3rd step: send new DFU_GETSTATUS request to check execution
dfuRequestResult = await stmDfuDevice.PerformControlTransferWithRetry(ud => stmDfuDevice.GetStatusAsync());
// Assert that the received buffer has the requested lenght
Assert.IsTrue(dfuRequestResult.BytesTransferred == StmDfuExtensions.GetStatusPacketLength);
// check DFU status
// status has to be different from STATUS_errTARGET
// state has to be different from STATE_DFU_ERROR
Assert.IsTrue(
dfuRequestResult.Data[0] != STATUS_errTARGET &&
dfuRequestResult.Data[4] != STATE_DFU_ERROR);
}
