From patchwork Thu Dec 14 23:08:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: RD Babiera X-Patchwork-Id: 13493804 Received: from mail-pf1-f202.google.com (mail-pf1-f202.google.com [209.85.210.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9BCD46FCEF for ; Thu, 14 Dec 2023 23:09:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--rdbabiera.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="K3WFMxg8" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-6ceb34b96fbso43190b3a.2 for ; Thu, 14 Dec 2023 15:09:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1702595350; x=1703200150; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=/qMULIQOgqIe7YMnzDJvKEyanw3KWMN0zaPdo/siE/M=; b=K3WFMxg8klWy2TlCXblniJgNtZj/l3LOx/ON3AccAstbIW00LGskQMU/cp4ion+660 ScoEQ5gbFieddeau/gn3daV2tW4MvfydDbgPR5ihdqdLIaO1BkyvTRwbopCnpBjPks+Y +kZc8NU+lOu07XwGWKwQ0RuShSciILWGU/HRAVlar6BzZZwDM1k6C3A8Ka3OgXTy4sbN GuD/D2sH2tzH1gyPl7fRxP9jPzjMiVRtWUgTfeEahN+kcVglfuRj0BAMF6ZcRbHvAQZT uKHxbQO/YJYiShWNqrrK7mc61quS0wp26/3gF+VOa4qr1g/5rPpGURimuSz1RCmSLZG/ gyrA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702595350; x=1703200150; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=/qMULIQOgqIe7YMnzDJvKEyanw3KWMN0zaPdo/siE/M=; b=v7m0oTzQ4viql/5G02gIieZJ4jLJP8TqcNUMgh87CgSFmZhRHZ2l31kQUp3TXWeC9h jLu0kCpszyo8Vjm1+VjkNfAbVyCXxryfsLGAWugGTwelUsgV264hFjDCvsail3VMWgbd BhhizysUbmICKS5m/wigUIO2Fog3QDAFKf5tLXNjR4o8VWYkJAG3MfC5l2J5K+X8bcNf g6x4FxvAG8HqqRVNPwnSPzKQQy307qGEDByWvuIDOLtfpM7WXh38ArVTDRZ28WIHFhwr +5eZKtsIWkeH7YP1rcKGKdoIQ6sDWx4OdD2wGznqMN7KLkHnLnOZT9pWYtqlaTatyfyl E7cw== X-Gm-Message-State: AOJu0YwX+rhcsa26TjKD8UXLllr8W9Qe8D0PB30D6RSi2qrToZzQwth+ pQkOmBESPA74pCPGSKVIcKVxRi+OfUXFggo= X-Google-Smtp-Source: AGHT+IG3pv/XkOk+37dZIvFdVEVcQz7AHVDMPa/trC3pJnVUwmwngUb5ADA2duKybR6KvhCTAhwcdJpEkEgOyK0= X-Received: from rdbabiera.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:18a8]) (user=rdbabiera job=sendgmr) by 2002:a05:6a00:1951:b0:6cd:f4a4:6438 with SMTP id s17-20020a056a00195100b006cdf4a46438mr1918589pfk.1.1702595349899; Thu, 14 Dec 2023 15:09:09 -0800 (PST) Date: Thu, 14 Dec 2023 23:08:50 +0000 In-Reply-To: <20231214230850.379863-14-rdbabiera@google.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231214230850.379863-14-rdbabiera@google.com> X-Developer-Key: i=rdbabiera@google.com; a=openpgp; fpr=639A331F1A21D691815CE090416E17CA2BBBD5C8 X-Developer-Signature: v=1; a=openpgp-sha256; l=14723; i=rdbabiera@google.com; h=from:subject; bh=Cts/QyqwRL0SscKvmL/gCe1wi0oepmxvRE5DukxwnmI=; b=owGbwMvMwCFW0bfok0KS4TbG02pJDKnV3azmm0pfMP1eIpebEf7G/467/amlBi2zd1TwJ6d/r w1+Lryjo5SFQYyDQVZMkUXXP8/gxpXULXM4a4xh5rAygQxh4OIUgIk8/8zwV2ryq9neT9dOTbBY tOkQ20fXy4uZ7Zk/eP2JT1cJtpKMXsfIMLGu7BLXU4Pn/hvi+Y6ddmSqvnPvjnShVEVgQdvnJQe bOAE= X-Mailer: git-send-email 2.43.0.472.g3155946c3a-goog Message-ID: <20231214230850.379863-20-rdbabiera@google.com> Subject: [PATCH v2 06/12] usb: typec: tcpm: add control message support to sop' From: RD Babiera To: rdbabiera@google.com, heikki.krogerus@linux.intel.com, linux@roeck-us.net, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Cc: badhri@google.com, bryan.odonoghue@linaro.org, agross@kernel.org, andersson@kernel.org, konrad.dybcio@linaro.org Add tx_sop_type to tcpm_pd_send_control and rx_sop_type to tcpm_pd_ctrl_request. TCPC_TX_SOP is added to all pd_send_control calls, but TCPC_TX_SOP_PRIME is added to pd_send_control for a SOFT_RESET message sent after a Vconn swap that makes the Port the Vconn source. Likewise, tcpm_pd_ctrl_request resets the proper protocol layer depending on rx_sop_type for SOFT_RESET. VCONN_SWAP_TURN_ON_VCONN now moves to a new state, VCONN_SWAP_SEND_SOFT_RESET. This state sends SOFT_RESET over SOP' before transitioning to the ready state if applicable. It transitions after PD_T_VCONN_STABLE, definied in pd.h as the time required for Vconn to be on before transmitting messages. Signed-off-by: RD Babiera Reviewed-by: Heikki Krogerus --- drivers/usb/typec/tcpm/tcpm.c | 159 ++++++++++++++++++++++++---------- include/linux/usb/pd.h | 1 + 2 files changed, 115 insertions(+), 45 deletions(-) diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index bc6c5f04e62f..c1e1fd6bd60d 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -108,6 +108,7 @@ S(VCONN_SWAP_WAIT_FOR_VCONN), \ S(VCONN_SWAP_TURN_ON_VCONN), \ S(VCONN_SWAP_TURN_OFF_VCONN), \ + S(VCONN_SWAP_SEND_SOFT_RESET), \ \ S(FR_SWAP_SEND), \ S(FR_SWAP_SEND_TIMEOUT), \ @@ -2388,7 +2389,8 @@ static inline enum tcpm_state ready_state(struct tcpm_port *port) } static int tcpm_pd_send_control(struct tcpm_port *port, - enum pd_ctrl_msg_type type); + enum pd_ctrl_msg_type type, + enum tcpm_transmit_type tx_sop_type); static void tcpm_handle_alert(struct tcpm_port *port, const __le32 *payload, int cnt) @@ -2742,10 +2744,12 @@ static void tcpm_pps_complete(struct tcpm_port *port, int result) } static void tcpm_pd_ctrl_request(struct tcpm_port *port, - const struct pd_message *msg) + const struct pd_message *msg, + enum tcpm_transmit_type rx_sop_type) { enum pd_ctrl_msg_type type = pd_header_type_le(msg->header); enum tcpm_state next_state; + unsigned int rev = pd_header_rev_le(msg->header); /* * Stop VDM state machine if interrupted by other Messages while NOT_SUPP is allowed in @@ -2910,6 +2914,16 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, case SOFT_RESET_SEND: if (port->ams == SOFT_RESET_AMS) tcpm_ams_finish(port); + /* + * SOP' Soft Reset is done after Vconn Swap, + * which returns to ready state + */ + if (rx_sop_type == TCPC_TX_SOP_PRIME) { + if (rev < port->negotiated_rev_prime) + port->negotiated_rev_prime = rev; + tcpm_set_state(port, ready_state(port), 0); + break; + } if (port->pwr_role == TYPEC_SOURCE) { port->upcoming_state = SRC_SEND_CAPABILITIES; tcpm_ams_start(port, POWER_NEGOTIATION); @@ -3109,8 +3123,7 @@ static void tcpm_pd_rx_handler(struct kthread_work *work) if (msgid == port->rx_msgid_prime) goto done; port->rx_msgid_prime = msgid; - /* Ignore SOP' for now */ - goto done; + break; case TCPC_TX_SOP: if (msgid == port->rx_msgid && type != PD_CTRL_SOFT_RESET) @@ -3140,7 +3153,7 @@ static void tcpm_pd_rx_handler(struct kthread_work *work) else if (cnt) tcpm_pd_data_request(port, msg); else - tcpm_pd_ctrl_request(port, msg); + tcpm_pd_ctrl_request(port, msg, rx_sop_type); } } @@ -3167,17 +3180,40 @@ void tcpm_pd_receive(struct tcpm_port *port, const struct pd_message *msg, EXPORT_SYMBOL_GPL(tcpm_pd_receive); static int tcpm_pd_send_control(struct tcpm_port *port, - enum pd_ctrl_msg_type type) + enum pd_ctrl_msg_type type, + enum tcpm_transmit_type tx_sop_type) { struct pd_message msg; memset(&msg, 0, sizeof(msg)); - msg.header = PD_HEADER_LE(type, port->pwr_role, - port->data_role, - port->negotiated_rev, - port->message_id, 0); + switch (tx_sop_type) { + case TCPC_TX_SOP_PRIME: + msg.header = PD_HEADER_LE(type, + 0, /* Cable Plug Indicator for DFP/UFP */ + 0, /* Reserved */ + port->negotiated_rev, + port->message_id_prime, + 0); + break; + case TCPC_TX_SOP: + msg.header = PD_HEADER_LE(type, + port->pwr_role, + port->data_role, + port->negotiated_rev, + port->message_id, + 0); + break; + default: + msg.header = PD_HEADER_LE(type, + port->pwr_role, + port->data_role, + port->negotiated_rev, + port->message_id, + 0); + break; + } - return tcpm_pd_transmit(port, TCPC_TX_SOP, &msg); + return tcpm_pd_transmit(port, tx_sop_type, &msg); } /* @@ -3196,13 +3232,13 @@ static bool tcpm_send_queued_message(struct tcpm_port *port) switch (queued_message) { case PD_MSG_CTRL_WAIT: - tcpm_pd_send_control(port, PD_CTRL_WAIT); + tcpm_pd_send_control(port, PD_CTRL_WAIT, TCPC_TX_SOP); break; case PD_MSG_CTRL_REJECT: - tcpm_pd_send_control(port, PD_CTRL_REJECT); + tcpm_pd_send_control(port, PD_CTRL_REJECT, TCPC_TX_SOP); break; case PD_MSG_CTRL_NOT_SUPP: - tcpm_pd_send_control(port, PD_CTRL_NOT_SUPP); + tcpm_pd_send_control(port, PD_CTRL_NOT_SUPP, TCPC_TX_SOP); break; case PD_MSG_DATA_SINK_CAP: ret = tcpm_pd_send_sink_caps(port); @@ -4217,7 +4253,7 @@ static void run_state_machine(struct tcpm_port *port) case SRC_NEGOTIATE_CAPABILITIES: ret = tcpm_pd_check_request(port); if (ret < 0) { - tcpm_pd_send_control(port, PD_CTRL_REJECT); + tcpm_pd_send_control(port, PD_CTRL_REJECT, TCPC_TX_SOP); if (!port->explicit_contract) { tcpm_set_state(port, SRC_WAIT_NEW_CAPABILITIES, 0); @@ -4225,7 +4261,7 @@ static void run_state_machine(struct tcpm_port *port) tcpm_set_state(port, SRC_READY, 0); } } else { - tcpm_pd_send_control(port, PD_CTRL_ACCEPT); + tcpm_pd_send_control(port, PD_CTRL_ACCEPT, TCPC_TX_SOP); tcpm_set_partner_usb_comm_capable(port, !!(port->sink_request & RDO_USB_COMM)); tcpm_set_state(port, SRC_TRANSITION_SUPPLY, @@ -4234,7 +4270,7 @@ static void run_state_machine(struct tcpm_port *port) break; case SRC_TRANSITION_SUPPLY: /* XXX: regulator_set_voltage(vbus, ...) */ - tcpm_pd_send_control(port, PD_CTRL_PS_RDY); + tcpm_pd_send_control(port, PD_CTRL_PS_RDY, TCPC_TX_SOP); port->explicit_contract = true; typec_set_pwr_opmode(port->typec_port, TYPEC_PWR_MODE_PD); port->pwr_opmode = TYPEC_PWR_MODE_PD; @@ -4718,7 +4754,7 @@ static void run_state_machine(struct tcpm_port *port) /* remove existing capabilities */ usb_power_delivery_unregister_capabilities(port->partner_source_caps); port->partner_source_caps = NULL; - tcpm_pd_send_control(port, PD_CTRL_ACCEPT); + tcpm_pd_send_control(port, PD_CTRL_ACCEPT, TCPC_TX_SOP); tcpm_ams_finish(port); if (port->pwr_role == TYPEC_SOURCE) { port->upcoming_state = SRC_SEND_CAPABILITIES; @@ -4735,28 +4771,41 @@ static void run_state_machine(struct tcpm_port *port) tcpm_ams_start(port, SOFT_RESET_AMS); break; case SOFT_RESET_SEND: - port->message_id = 0; - port->rx_msgid = -1; - /* remove existing capabilities */ - usb_power_delivery_unregister_capabilities(port->partner_source_caps); - port->partner_source_caps = NULL; - if (tcpm_pd_send_control(port, PD_CTRL_SOFT_RESET)) - tcpm_set_state_cond(port, hard_reset_state(port), 0); - else - tcpm_set_state_cond(port, hard_reset_state(port), - PD_T_SENDER_RESPONSE); + /* + * Power Delivery 3.0 Section 6.3.13 + * + * A Soft_Reset Message Shall be targeted at a specific entity + * depending on the type of SOP* packet used. + */ + if (port->tx_sop_type == TCPC_TX_SOP_PRIME) { + port->message_id_prime = 0; + port->rx_msgid_prime = -1; + tcpm_pd_send_control(port, PD_CTRL_SOFT_RESET, TCPC_TX_SOP_PRIME); + tcpm_set_state_cond(port, ready_state(port), PD_T_SENDER_RESPONSE); + } else { + port->message_id = 0; + port->rx_msgid = -1; + /* remove existing capabilities */ + usb_power_delivery_unregister_capabilities(port->partner_source_caps); + port->partner_source_caps = NULL; + if (tcpm_pd_send_control(port, PD_CTRL_SOFT_RESET, TCPC_TX_SOP)) + tcpm_set_state_cond(port, hard_reset_state(port), 0); + else + tcpm_set_state_cond(port, hard_reset_state(port), + PD_T_SENDER_RESPONSE); + } break; /* DR_Swap states */ case DR_SWAP_SEND: - tcpm_pd_send_control(port, PD_CTRL_DR_SWAP); + tcpm_pd_send_control(port, PD_CTRL_DR_SWAP, TCPC_TX_SOP); if (port->data_role == TYPEC_DEVICE || port->negotiated_rev > PD_REV20) port->send_discover = true; tcpm_set_state_cond(port, DR_SWAP_SEND_TIMEOUT, PD_T_SENDER_RESPONSE); break; case DR_SWAP_ACCEPT: - tcpm_pd_send_control(port, PD_CTRL_ACCEPT); + tcpm_pd_send_control(port, PD_CTRL_ACCEPT, TCPC_TX_SOP); if (port->data_role == TYPEC_DEVICE || port->negotiated_rev > PD_REV20) port->send_discover = true; tcpm_set_state_cond(port, DR_SWAP_CHANGE_DR, 0); @@ -4780,7 +4829,7 @@ static void run_state_machine(struct tcpm_port *port) break; case FR_SWAP_SEND: - if (tcpm_pd_send_control(port, PD_CTRL_FR_SWAP)) { + if (tcpm_pd_send_control(port, PD_CTRL_FR_SWAP, TCPC_TX_SOP)) { tcpm_set_state(port, ERROR_RECOVERY, 0); break; } @@ -4800,7 +4849,7 @@ static void run_state_machine(struct tcpm_port *port) break; case FR_SWAP_SNK_SRC_SOURCE_VBUS_APPLIED: tcpm_set_pwr_role(port, TYPEC_SOURCE); - if (tcpm_pd_send_control(port, PD_CTRL_PS_RDY)) { + if (tcpm_pd_send_control(port, PD_CTRL_PS_RDY, TCPC_TX_SOP)) { tcpm_set_state(port, ERROR_RECOVERY, 0); break; } @@ -4810,11 +4859,11 @@ static void run_state_machine(struct tcpm_port *port) /* PR_Swap states */ case PR_SWAP_ACCEPT: - tcpm_pd_send_control(port, PD_CTRL_ACCEPT); + tcpm_pd_send_control(port, PD_CTRL_ACCEPT, TCPC_TX_SOP); tcpm_set_state(port, PR_SWAP_START, 0); break; case PR_SWAP_SEND: - tcpm_pd_send_control(port, PD_CTRL_PR_SWAP); + tcpm_pd_send_control(port, PD_CTRL_PR_SWAP, TCPC_TX_SOP); tcpm_set_state_cond(port, PR_SWAP_SEND_TIMEOUT, PD_T_SENDER_RESPONSE); break; @@ -4856,7 +4905,7 @@ static void run_state_machine(struct tcpm_port *port) * supply is turned off" */ tcpm_set_pwr_role(port, TYPEC_SINK); - if (tcpm_pd_send_control(port, PD_CTRL_PS_RDY)) { + if (tcpm_pd_send_control(port, PD_CTRL_PS_RDY, TCPC_TX_SOP)) { tcpm_set_state(port, ERROR_RECOVERY, 0); break; } @@ -4903,17 +4952,17 @@ static void run_state_machine(struct tcpm_port *port) * Source." */ tcpm_set_pwr_role(port, TYPEC_SOURCE); - tcpm_pd_send_control(port, PD_CTRL_PS_RDY); + tcpm_pd_send_control(port, PD_CTRL_PS_RDY, TCPC_TX_SOP); tcpm_set_state(port, SRC_STARTUP, PD_T_SWAP_SRC_START); break; case VCONN_SWAP_ACCEPT: - tcpm_pd_send_control(port, PD_CTRL_ACCEPT); + tcpm_pd_send_control(port, PD_CTRL_ACCEPT, TCPC_TX_SOP); tcpm_ams_finish(port); tcpm_set_state(port, VCONN_SWAP_START, 0); break; case VCONN_SWAP_SEND: - tcpm_pd_send_control(port, PD_CTRL_VCONN_SWAP); + tcpm_pd_send_control(port, PD_CTRL_VCONN_SWAP, TCPC_TX_SOP); tcpm_set_state(port, VCONN_SWAP_SEND_TIMEOUT, PD_T_SENDER_RESPONSE); break; @@ -4932,14 +4981,34 @@ static void run_state_machine(struct tcpm_port *port) PD_T_VCONN_SOURCE_ON); break; case VCONN_SWAP_TURN_ON_VCONN: - tcpm_set_vconn(port, true); - tcpm_pd_send_control(port, PD_CTRL_PS_RDY); - tcpm_set_state(port, ready_state(port), 0); + ret = tcpm_set_vconn(port, true); + tcpm_pd_send_control(port, PD_CTRL_PS_RDY, TCPC_TX_SOP); + /* + * USB PD 3.0 Section 6.4.4.3.1 + * + * Note that a Cable Plug or VPD will not be ready for PD + * Communication until tVCONNStable after VCONN has been applied + */ + if (!ret) + tcpm_set_state(port, VCONN_SWAP_SEND_SOFT_RESET, + PD_T_VCONN_STABLE); + else + tcpm_set_state(port, ready_state(port), 0); break; case VCONN_SWAP_TURN_OFF_VCONN: tcpm_set_vconn(port, false); tcpm_set_state(port, ready_state(port), 0); break; + case VCONN_SWAP_SEND_SOFT_RESET: + tcpm_swap_complete(port, port->swap_status); + if (tcpm_can_communicate_sop_prime(port)) { + port->tx_sop_type = TCPC_TX_SOP_PRIME; + port->upcoming_state = SOFT_RESET_SEND; + tcpm_ams_start(port, SOFT_RESET_AMS); + } else { + tcpm_set_state(port, ready_state(port), 0); + } + break; case DR_SWAP_CANCEL: case PR_SWAP_CANCEL: @@ -4975,7 +5044,7 @@ static void run_state_machine(struct tcpm_port *port) } break; case GET_STATUS_SEND: - tcpm_pd_send_control(port, PD_CTRL_GET_STATUS); + tcpm_pd_send_control(port, PD_CTRL_GET_STATUS, TCPC_TX_SOP); tcpm_set_state(port, GET_STATUS_SEND_TIMEOUT, PD_T_SENDER_RESPONSE); break; @@ -4983,7 +5052,7 @@ static void run_state_machine(struct tcpm_port *port) tcpm_set_state(port, ready_state(port), 0); break; case GET_PPS_STATUS_SEND: - tcpm_pd_send_control(port, PD_CTRL_GET_PPS_STATUS); + tcpm_pd_send_control(port, PD_CTRL_GET_PPS_STATUS, TCPC_TX_SOP); tcpm_set_state(port, GET_PPS_STATUS_SEND_TIMEOUT, PD_T_SENDER_RESPONSE); break; @@ -4991,7 +5060,7 @@ static void run_state_machine(struct tcpm_port *port) tcpm_set_state(port, ready_state(port), 0); break; case GET_SINK_CAP: - tcpm_pd_send_control(port, PD_CTRL_GET_SINK_CAP); + tcpm_pd_send_control(port, PD_CTRL_GET_SINK_CAP, TCPC_TX_SOP); tcpm_set_state(port, GET_SINK_CAP_TIMEOUT, PD_T_SENDER_RESPONSE); break; case GET_SINK_CAP_TIMEOUT: @@ -5031,7 +5100,7 @@ static void run_state_machine(struct tcpm_port *port) /* Chunk state */ case CHUNK_NOT_SUPP: - tcpm_pd_send_control(port, PD_CTRL_NOT_SUPP); + tcpm_pd_send_control(port, PD_CTRL_NOT_SUPP, TCPC_TX_SOP); tcpm_set_state(port, port->pwr_role == TYPEC_SOURCE ? SRC_READY : SNK_READY, 0); break; default: diff --git a/include/linux/usb/pd.h b/include/linux/usb/pd.h index eb626af0e4e7..d50098fb16b5 100644 --- a/include/linux/usb/pd.h +++ b/include/linux/usb/pd.h @@ -483,6 +483,7 @@ static inline unsigned int rdo_max_power(u32 rdo) #define PD_T_BIST_CONT_MODE 50 /* 30 - 60 ms */ #define PD_T_SINK_TX 16 /* 16 - 20 ms */ #define PD_T_CHUNK_NOT_SUPP 42 /* 40 - 50 ms */ +#define PD_T_VCONN_STABLE 50 #define PD_T_DRP_TRY 100 /* 75 - 150 ms */ #define PD_T_DRP_TRYWAIT 600 /* 400 - 800 ms */