[diag] Handle errors of TransmitPacket()

`TransmitPacket()` should return an error from platform Radio
implementation, as for example Radio can be in incorrect state.

If error occurs, output it onto console.

Add wrong state case to tests and fix `diag repeat stop` called
too lata.

Signed-off-by: Maciej Baczmanski <maciej.baczmanski@nordicsemi.no>

Author: maciejbaczmanski

src/core/diags/factory_diags.cpp

@@ -450,7 +450,7 @@ Error Diags::ProcessSend(uint8_t aArgsLength, char *aArgs[])
     VerifyOrExit(txLength >= OT_RADIO_FRAME_MIN_SIZE, error = kErrorInvalidArgs);
     mTxLen = txLength;
 
-    TransmitPacket();
+    SuccessOrExit(error = TransmitPacket());
 
 exit:
     return error;
@@ -528,8 +528,9 @@ Error Diags::ProcessStop(uint8_t aArgsLength, char *aArgs[])
     return kErrorNone;
 }
 
-void Diags::TransmitPacket(void)
+Error Diags::TransmitPacket(void)
 {
+    Error error = kErrorNone;
     mTxPacket->mChannel = mChannel;
 
     if (mIsTxPacketSet)
@@ -550,7 +551,14 @@ void Diags::TransmitPacket(void)
     }
 
     mDiagSendOn = true;
-    IgnoreError(Get<Radio>().Transmit(*static_cast<Mac::TxFrame *>(mTxPacket)));
+    error = Get<Radio>().Transmit(*static_cast<Mac::TxFrame *>(mTxPacket));
+
+    if(error != kErrorNone)
+    {
+        Output("Packet transmission failed, error: %s\r\n", ErrorToString(error));
+    }
+
+    return error;
 }
 
 Error Diags::ParseReceiveConfigFormat(const char *aFormat, ReceiveConfig &aConfig)
@@ -747,7 +755,7 @@ void Diags::AlarmFired(void)
     {
         uint32_t now = otPlatAlarmMilliGetNow();
 
-        TransmitPacket();
+        IgnoreError(TransmitPacket());
         otPlatAlarmMilliStartAt(&GetInstance(), now, mTxPeriod);
     }
     else
@@ -856,7 +864,7 @@ void Diags::TransmitDone(Error aError)
     VerifyOrExit(mTxPackets > 1);
     mTxPackets--;
 
-    TransmitPacket();
+    IgnoreError(TransmitPacket());
 
 exit:
     return;

src/core/diags/factory_diags.hpp

@@ -232,10 +232,10 @@ class Diags : public InstanceLocator, private NonCopyable
     Error GetPowerSettings(uint8_t aChannel, PowerSettings &aPowerSettings);
     Error ParseReceiveConfigFormat(const char *aFormat, ReceiveConfig &aConfig);
     Error RadioReceive(void);
+    Error TransmitPacket(void);
     void  OutputReceivedFrame(const otRadioFrame *aFrame);
     bool  ShouldHandleReceivedFrame(const otRadioFrame &aFrame) const;
 
-    void TransmitPacket(void);
     void Output(const char *aFormat, ...);
     void ResetTxPacket(void);
     void OutputStats(void);

tests/scripts/expect/cli-diags.exp

@@ -127,6 +127,22 @@ send_user "input odd length test\n"
 send "diag frame 123\n"
 expect "Error"
 
+send "diag radio sleep\n"
+expect_line "Done"
+
+send "diag radio disable\n"
+expect_line "Done"
+
+send "diag send 10 10\n"
+expect "Packet transmission failed, error: InvalidState"
+expect "Error 13: InvalidState"
+
+send "diag radio enable\n"
+expect_line "Done"
+
+send "diag radio receive\n"
+expect_line "Done"
+
 send_user "shortest frame test\n"
 send "diag frame 112233\n"
 expect "Done"
@@ -138,6 +154,9 @@ send "diag frame 112233445566778899001122334455667788990011223344556677889900112
 expect "Done"
 send "diag repeat 1\n"
 expect "Done"
+sleep 3
+send "diag repeat stop\n"
+expect "Done"
 
 send_user "send frame with security processed\n"
 send "diag frame -s 112233\n"
@@ -157,9 +176,6 @@ expect "Done"
 send "diag send 1\n"
 expect "Done"
 
-send "diag repeat stop\n"
-expect "Done"
-
 send "diag channel 11\n"
 expect_line "Done"