usb: typec: tcpm: Properly handle Alert and Status Messages

When receiving Alert Message, if it is not unexpected but is
unsupported for some reason, the port should return Not_Supported
Message response.

Also, according to PD3.0 Spec 6.5.2.1.4 Event Flags Field, the
OTP/OVP/OCP flags in the Event Flags field in Status Message no longer
require Get_PPS_Status Message to clear them. Thus remove it when
receiving Status Message with those flags being set.

In addition, add the missing AMS operations for Status Message.

Fixes: 64f7c494a3c0 ("typec: tcpm: Add support for sink PPS related messages")
Fixes: 0908c5aca31e ("usb: typec: tcpm: AMS and Collision Avoidance")
Signed-off-by: Kyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20210531164928.2368606-1-kyletso@google.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 6161a0c..938a1af 100644 (file)
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -2188,20 +2188,25 @@ static void tcpm_handle_alert(struct tcpm_port *port, const __le32 *payload,
 
        if (!type) {
                tcpm_log(port, "Alert message received with no type");
+               tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
                return;
        }
 
        /* Just handling non-battery alerts for now */
        if (!(type & USB_PD_ADO_TYPE_BATT_STATUS_CHANGE)) {
-               switch (port->state) {
-               case SRC_READY:
-               case SNK_READY:
+               if (port->pwr_role == TYPEC_SOURCE) {
+                       port->upcoming_state = GET_STATUS_SEND;
+                       tcpm_ams_start(port, GETTING_SOURCE_SINK_STATUS);
+               } else {
+                       /*
+                        * Do not check SinkTxOk here in case the Source doesn't set its Rp to
+                        * SinkTxOk in time.
+                        */
+                       port->ams = GETTING_SOURCE_SINK_STATUS;
                        tcpm_set_state(port, GET_STATUS_SEND, 0);
-                       break;
-               default:
-                       tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
-                       break;
                }
+       } else {
+               tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
        }
 }
 
@@ -2445,7 +2450,12 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
                tcpm_pd_handle_state(port, BIST_RX, BIST, 0);
                break;
        case PD_DATA_ALERT:
-               tcpm_handle_alert(port, msg->payload, cnt);
+               if (port->state != SRC_READY && port->state != SNK_READY)
+                       tcpm_pd_handle_state(port, port->pwr_role == TYPEC_SOURCE ?
+                                            SRC_SOFT_RESET_WAIT_SNK_TX : SNK_SOFT_RESET,
+                                            NONE_AMS, 0);
+               else
+                       tcpm_handle_alert(port, msg->payload, cnt);
                break;
        case PD_DATA_BATT_STATUS:
        case PD_DATA_GET_COUNTRY_INFO:
@@ -2769,24 +2779,16 @@ static void tcpm_pd_ext_msg_request(struct tcpm_port *port,
 
        switch (type) {
        case PD_EXT_STATUS:
-               /*
-                * If PPS related events raised then get PPS status to clear
-                * (see USB PD 3.0 Spec, 6.5.2.4)
-                */
-               if (msg->ext_msg.data[USB_PD_EXT_SDB_EVENT_FLAGS] &
-                   USB_PD_EXT_SDB_PPS_EVENTS)
-                       tcpm_pd_handle_state(port, GET_PPS_STATUS_SEND,
-                                            GETTING_SOURCE_SINK_STATUS, 0);
-
-               else
-                       tcpm_pd_handle_state(port, ready_state(port), NONE_AMS, 0);
-               break;
        case PD_EXT_PPS_STATUS:
-               /*
-                * For now the PPS status message is used to clear events
-                * and nothing more.
-                */
-               tcpm_pd_handle_state(port, ready_state(port), NONE_AMS, 0);
+               if (port->ams == GETTING_SOURCE_SINK_STATUS) {
+                       tcpm_ams_finish(port);
+                       tcpm_set_state(port, ready_state(port), 0);
+               } else {
+                       /* unexpected Status or PPS_Status Message */
+                       tcpm_pd_handle_state(port, port->pwr_role == TYPEC_SOURCE ?
+                                            SRC_SOFT_RESET_WAIT_SNK_TX : SNK_SOFT_RESET,
+                                            NONE_AMS, 0);
+               }
                break;
        case PD_EXT_SOURCE_CAP_EXT:
        case PD_EXT_GET_BATT_CAP:

diff --git a/include/linux/usb/pd_ext_sdb.h b/include/linux/usb/pd_ext_sdb.h
index 0eb83ce..b517ebc 100644 (file)
--- a/include/linux/usb/pd_ext_sdb.h
+++ b/include/linux/usb/pd_ext_sdb.h
@@ -24,8 +24,4 @@ enum usb_pd_ext_sdb_fields {
 #define USB_PD_EXT_SDB_EVENT_OVP               BIT(3)
 #define USB_PD_EXT_SDB_EVENT_CF_CV_MODE                BIT(4)
 
-#define USB_PD_EXT_SDB_PPS_EVENTS      (USB_PD_EXT_SDB_EVENT_OCP |     \
-                                        USB_PD_EXT_SDB_EVENT_OTP |     \
-                                        USB_PD_EXT_SDB_EVENT_OVP)
-
 #endif /* __LINUX_USB_PD_EXT_SDB_H */