From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755779AbdEIQG2 (ORCPT ); Tue, 9 May 2017 12:06:28 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:46448 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755032AbdEIQFP (ORCPT ); Tue, 9 May 2017 12:05:15 -0400 From: Guenter Roeck To: Greg Kroah-Hartman Cc: Yueyao Zhu , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Guenter Roeck Subject: [PATCH 4/7] staging: typec: tcpm: Drop duplicate PD messages Date: Tue, 9 May 2017 09:04:56 -0700 Message-Id: <1494345899-14283-4-git-send-email-linux@roeck-us.net> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1494345899-14283-1-git-send-email-linux@roeck-us.net> References: <1494345899-14283-1-git-send-email-linux@roeck-us.net> X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: guenter@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: guenter@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Per USB PD standard, we have to drop duplicate PD messages. We can not expect lower protocol layers to drop such messages, since lower layers don't know if a message was dropped somewhere else in the stack. Originally-from: Puma Hsu Cc: Yueyao Zhu Signed-off-by: Guenter Roeck --- drivers/staging/typec/pd.h | 10 ++++++++++ drivers/staging/typec/tcpm.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/drivers/staging/typec/pd.h b/drivers/staging/typec/pd.h index 8d97bdb95f23..510ef7279900 100644 --- a/drivers/staging/typec/pd.h +++ b/drivers/staging/typec/pd.h @@ -92,6 +92,16 @@ static inline unsigned int pd_header_type_le(__le16 header) return pd_header_type(le16_to_cpu(header)); } +static inline unsigned int pd_header_msgid(u16 header) +{ + return (header >> PD_HEADER_ID_SHIFT) & PD_HEADER_ID_MASK; +} + +static inline unsigned int pd_header_msgid_le(__le16 header) +{ + return pd_header_msgid(le16_to_cpu(header)); +} + #define PD_MAX_PAYLOAD 7 struct pd_message { diff --git a/drivers/staging/typec/tcpm.c b/drivers/staging/typec/tcpm.c index abba655ba00a..c5d8b129c4f4 100644 --- a/drivers/staging/typec/tcpm.c +++ b/drivers/staging/typec/tcpm.c @@ -238,6 +238,7 @@ struct tcpm_port { unsigned int hard_reset_count; bool pd_capable; bool explicit_contract; + unsigned int rx_msgid; /* Partner capabilities/requests */ u32 sink_request; @@ -1415,6 +1416,7 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, break; case SOFT_RESET_SEND: port->message_id = 0; + port->rx_msgid = -1; if (port->pwr_role == TYPEC_SOURCE) next_state = SRC_SEND_CAPABILITIES; else @@ -1503,6 +1505,22 @@ static void tcpm_pd_rx_handler(struct work_struct *work) port->attached); if (port->attached) { + enum pd_ctrl_msg_type type = pd_header_type_le(msg->header); + unsigned int msgid = pd_header_msgid_le(msg->header); + + /* + * USB PD standard, 6.6.1.2: + * "... if MessageID value in a received Message is the + * same as the stored value, the receiver shall return a + * GoodCRC Message with that MessageID value and drop + * the Message (this is a retry of an already received + * Message). Note: this shall not apply to the Soft_Reset + * Message which always has a MessageID value of zero." + */ + if (msgid == port->rx_msgid && type != PD_CTRL_SOFT_RESET) + goto done; + port->rx_msgid = msgid; + /* * If both ends believe to be DFP/host, we have a data role * mismatch. @@ -1520,6 +1538,7 @@ static void tcpm_pd_rx_handler(struct work_struct *work) } } +done: mutex_unlock(&port->lock); kfree(event); } @@ -1957,6 +1976,12 @@ static void tcpm_reset_port(struct tcpm_port *port) port->attached = false; port->pd_capable = false; + /* + * First Rx ID should be 0; set this to a sentinel of -1 so that + * we can check tcpm_pd_rx_handler() if we had seen it before. + */ + port->rx_msgid = -1; + port->tcpc->set_pd_rx(port->tcpc, false); tcpm_init_vbus(port); /* also disables charging */ tcpm_init_vconn(port); @@ -2170,6 +2195,7 @@ static void run_state_machine(struct tcpm_port *port) port->pwr_opmode = TYPEC_PWR_MODE_USB; port->caps_count = 0; port->message_id = 0; + port->rx_msgid = -1; port->explicit_contract = false; tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0); break; @@ -2329,6 +2355,7 @@ static void run_state_machine(struct tcpm_port *port) typec_set_pwr_opmode(port->typec_port, TYPEC_PWR_MODE_USB); port->pwr_opmode = TYPEC_PWR_MODE_USB; port->message_id = 0; + port->rx_msgid = -1; port->explicit_contract = false; tcpm_set_state(port, SNK_DISCOVERY, 0); break; @@ -2496,6 +2523,7 @@ static void run_state_machine(struct tcpm_port *port) /* Soft_Reset states */ case SOFT_RESET: port->message_id = 0; + port->rx_msgid = -1; tcpm_pd_send_control(port, PD_CTRL_ACCEPT); if (port->pwr_role == TYPEC_SOURCE) tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0); @@ -2504,6 +2532,7 @@ static void run_state_machine(struct tcpm_port *port) break; case SOFT_RESET_SEND: port->message_id = 0; + port->rx_msgid = -1; if (tcpm_pd_send_control(port, PD_CTRL_SOFT_RESET)) tcpm_set_state_cond(port, hard_reset_state(port), 0); else -- 2.7.4