TCPMv2: Fixed PR swap request from charge manager

The PR swap request from the charge manager was locking up the
TC state machine. The pd_request_power_swap function was changed
so that it sends the request to the policy engine instead of
initiating it directly.

BUG=chromium:1027247
BRANCH=none
TEST=make -j buildall
	Tested with apple dongle "A2119 2019 HBR3" known to reproduce this
	problem.

Change-Id: Ic59036056434ed525a839cd781cff93e3b5bfc53
Signed-off-by: Sam Hurst <shurst@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1928795
Reviewed-by: Denis Brockus <dbrockus@chromium.org>
Reviewed-by: Jett Rink <jettrink@chromium.org>

5 files changed, 20 insertions, 6 deletions

diff --git a/common/usbc/usb_pe_drp_sm.c b/common/usbc/usb_pe_drp_sm.c
index 590a72640d..8f68a5db3e 100644
--- a/common/usbc/usb_pe_drp_sm.c
+++ b/common/usbc/usb_pe_drp_sm.c
@@ -931,6 +931,11 @@ static void pe_update_pdo_flags(int port, uint32_t pdo)
 #endif
 }
 
+void pd_request_power_swap(int port)
+{
+	pe_dpm_request(port, DPM_REQUEST_PR_SWAP);
+}
+
 int pd_is_port_partner_dualrole(int port)
 {
 	return PE_CHK_FLAG(port, PE_FLAGS_PORT_PARTNER_IS_DUALROLE);
@@ -2894,7 +2899,7 @@ static void pe_prs_src_snk_evaluate_swap_entry(int port)
 		/* PE_PRS_SRC_SNK_Reject_PR_Swap state embedded here */
 		prl_send_ctrl_msg(port, TCPC_TX_SOP, PD_CTRL_REJECT);
 	} else {
-		pd_request_power_swap(port);
+		tc_request_power_swap(port);
 		/* PE_PRS_SRC_SNK_Accept_Swap state embedded here */
 		PE_SET_FLAG(port, PE_FLAGS_ACCEPT);
 		prl_send_ctrl_msg(port, TCPC_TX_SOP, PD_CTRL_ACCEPT);
@@ -3080,7 +3085,7 @@ static void pe_prs_snk_src_evaluate_swap_entry(int port)
 		/* PE_PRS_SNK_SRC_Reject_Swap state embedded here */
 		prl_send_ctrl_msg(port, TCPC_TX_SOP, PD_CTRL_REJECT);
 	} else {
-		pd_request_power_swap(port);
+		tc_request_power_swap(port);
 		/* PE_PRS_SNK_SRC_Accept_Swap state embedded here */
 		PE_SET_FLAG(port, PE_FLAGS_ACCEPT);
 		prl_send_ctrl_msg(port, TCPC_TX_SOP, PD_CTRL_ACCEPT);
diff --git a/common/usbc/usb_tc_drp_acc_trysrc_sm.c b/common/usbc/usb_tc_drp_acc_trysrc_sm.c
index a3e6f5f67f..c0169d704a 100644
--- a/common/usbc/usb_tc_drp_acc_trysrc_sm.c
+++ b/common/usbc/usb_tc_drp_acc_trysrc_sm.c
@@ -366,7 +366,7 @@ void pd_set_new_power_request(int port)
 	}
 }
 
-void pd_request_power_swap(int port)
+void tc_request_power_swap(int port)
 {
 	if (IS_ENABLED(CONFIG_USB_PE_SM)) {
 		/*
diff --git a/include/usb_tc_sm.h b/include/usb_tc_sm.h
index f94360ad3f..b4b559152f 100644
--- a/include/usb_tc_sm.h
+++ b/include/usb_tc_sm.h
@@ -177,6 +177,14 @@ void tc_prs_src_snk_assert_rd(int port);
 void tc_prs_snk_src_assert_rp(int port);
 
 /**
+ * Informs the Type-C State Machine that a Power Role Swap is starting.
+ * This function is called from the Policy Engine.
+ *
+ * @parm port USB_C port number
+ */
+void tc_request_power_swap(int port);
+
+/**
  * Informs the Type-C State Machine that a Power Role Swap is complete.
  * This function is called from the Policy Engine.
  *
diff --git a/test/fake_usbc.c b/test/fake_usbc.c
index b0137cb893..a563f3d4d8 100644
--- a/test/fake_usbc.c
+++ b/test/fake_usbc.c
@@ -16,9 +16,6 @@ int pd_is_vbus_present(int port)
 void pd_request_data_swap(int port)
 {}
 
-void pd_request_power_swap(int port)
-{}
-
 void pd_request_vconn_swap_off(int port)
 {}
 
diff --git a/test/usb_pe_drp.c b/test/usb_pe_drp.c
index c6a1dc0af7..e8167cc1ac 100644
--- a/test/usb_pe_drp.c
+++ b/test/usb_pe_drp.c
@@ -29,6 +29,10 @@ int board_vbus_source_enabled(int port)
 {
 	return 0;
 }
+void tc_request_power_swap(int port)
+{
+	/* Do nothing */
+}
 
 /**
  * Test section