stm32g431 ucpd sink USBPD_DPM_RequestMessageRequest busy forever

[IvanFromCyberia]

Hello,

I am running STM32G431 board with USBC PD feature.

CubeIDE 1.14.1

I am trying to bring up the UCPD stack.

I refer the basic guideline:

https://wiki.st.com/stm32mcu/wiki/STM32StepByStep:Getting_started_with_USB-Power_Delivery_Sink

It worked ideally.

Next step I made 2 simple steps:

1. Save Source capabilities (parse and display it on default thread):

case USBPD_CORE_DATATYPE_RCV_SRC_PDO: /*!< Storage of Received Source PDO values */
     memcpy(my_pdo_rdo_ctrl.pdo, Ptr, Size);
     my_pdo_rdo_ctrl.num_of_pdo = Size/4;

     b. Send request with my function (also on default thread):

USBPD_StatusTypeDef USBPD_DPM_RequestMessageRequest_fix(uint8_t IndexSrcPDO){

  USBPD_StatusTypeDef _status = USBPD_ERROR;

  USBPD_SNKRDO_TypeDef rdo;

  rdo.d32 = 0;

  rdo.GenericRDO.ObjectPosition = IndexSrcPDO;

  rdo.FixedVariableRDO.OperatingCurrentIn10mAunits = my_pdo_rdo_ctrl.pdo[IndexSrcPDO - 1].SRCFixedPDO.MaxCurrentIn10mAunits;
  rdo.FixedVariableRDO.MaxOperatingCurrent10mAunits = my_pdo_rdo_ctrl.pdo[IndexSrcPDO - 1].SRCFixedPDO.MaxCurrentIn10mAunits;

  _status = USBPD_PE_Send_Request(0, rdo.d32, USBPD_CORE_PDO_TYPE_FIXED);
  ucpd_printf(0, "FIX USBPD_DPM_RequestMessageRequest %x", _status);
  return _status;
}​

Eventually I get this capabilities from my power supply:

0	IN	256	0	SOP	 PD3	s:026	    H:0x63A1    	(id:1, DR:DFP, PR:SRC) 	SRC_CAPABILITIES	DATA: 2C9101082CD102002CC103002CB10400F44106006421A4C1	
Option: 	EPW	 
[1] Fixed : 5V - 3A /  
[2] Fixed : 9V - 3A /  
[3] Fixed : 12V - 3A /  
[4] Fixed : 15V - 3A /  
[5] Fixed : 20V - 5A /  
[6] Programmable : [3.3V - 21V] - 5A / 

Using this information, I call every 5 second either one:

USBPD_DPM_RequestMessageRequest_fix(2)

or

USBPD_DPM_RequestMessageRequest_fix(3)

It operates normally, and I can see requested voltages 9 and 12 volts changing.

However, after some time (always different), the USBPD_DPM_RequestMessageRequest_fix reports it is BUSY, and without reason communications with power supply is not seen.

This is my log:

2841	PE	640288	0	PE_STATE_READY_WAIT
2842	PE	645150	0	PE_SNK_SEND_REQUEST
2843	OUT	645150	0	SOP	 PD3	REQUEST	s:006	    H:0x1282    	(id:1, DR:UFP, PR:SNK)  DATA: 2CB10420 / ObjectPosition:2 / GiveBack:0 / CapabilityMismatch:0 / USBCommunicationCapable:0 / NoUSBSuspend:0 / UnchunkedExtendedMessagesSupported:0 / MaximumOperatingCurrent:440mA / OperatingCurrent:3000mA
2844	IN	645151	0	SOP	s:002	    H:0x0321     (id:1, DR:DFP, PR:SRC) 	GOODCRC
2845	PE	645151	0	PE_SNK_SELECT_CAPABILITY
2846	DEBUG	645151	0	FIX USBPD_DPM_RequestMessageRequest 0
2847	IN	645155	0	SOP	 PD3	ACCEPT	s:002	    H:0x09A3     (id:4, DR:DFP, PR:SRC) 
2848	OUT	645155	0	SOP	s:002	    H:0x0841     (id:4, DR:UFP, PR:SNK) 	GOODCRC
2849	NOTIF	645155	0	POWER_STATE_CHANGE
2850	DEBUG	645155	0	ADVICE: USBPD_DPM_Notification:90
2851	NOTIF	645155	0	REQUEST_ACCEPTED
2852	DEBUG	645155	0	ADVICE: USBPD_DPM_Notification:1
2853	PE	645156	0	PE_SNK_TRANSITION_SNK
2854	IN	645287	0	SOP	 PD3	PS_RDY	s:002	    H:0x0BA6     (id:5, DR:DFP, PR:SRC) 
2855	OUT	645287	0	SOP	s:002	    H:0x0A41     (id:5, DR:UFP, PR:SNK) 	GOODCRC
2856	NOTIF	645288	0	POWER_STATE_CHANGE
2857	DEBUG	645288	0	ADVICE: USBPD_DPM_Notification:90
2858	NOTIF	645288	0	POWER_EXPLICIT_CONTRACT
2859	DEBUG	645288	0	ADVICE: USBPD_DPM_Notification:16
2860	PE	645288	0	PE_STATE_READY
2861	NOTIF	645288	0	STATE_SNK_READY
2862	DEBUG	645288	0	ADVICE: USBPD_DPM_Notification:32
2863	PE	645288	0	PE_STATE_READY_WAIT
2864	DEBUG	650151	0	FIX USBPD_DPM_RequestMessageRequest 0
2865	DEBUG	655151	0	FIX USBPD_DPM_RequestMessageRequest 3
2866	DEBUG	660151	0	FIX USBPD_DPM_RequestMessageRequest 3

USBPD_DPM_RequestMessageRequest 3 ---->>> USBPD_BUSY,

Simple Unplug-Plug USB cable restarts UCPD stack and it again operates normally until stops again the same way after some time.

I searched for reasonable explanation, but cannot find - what may be the reason of this behaviour? Is it bug or feature? How to debug it?

I observe this with some of UCPD power supplies I have. Not all.

Please help.

Kind regards,

Ivan.

[FBL]

Hello @IvanFromCyberia 

Would you share the trace .cpd ?