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[23.128.96.18]) by mx.google.com with ESMTP id 6si7413964ill.90.2021.08.23.00.16.20; Mon, 23 Aug 2021 00:16:32 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=ETLmekkW; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234976AbhHWHPy (ORCPT + 99 others); Mon, 23 Aug 2021 03:15:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41742 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234999AbhHWHPy (ORCPT ); Mon, 23 Aug 2021 03:15:54 -0400 Received: from mail-il1-x12b.google.com (mail-il1-x12b.google.com [IPv6:2607:f8b0:4864:20::12b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3FCEFC061756 for ; Mon, 23 Aug 2021 00:15:12 -0700 (PDT) Received: by mail-il1-x12b.google.com with SMTP id x5so16169015ill.3 for ; Mon, 23 Aug 2021 00:15:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=SQ2Uwhj6FDqhZFG4Jra0608BEmKaZpqCAcRucXb8YWg=; b=ETLmekkWV6Pon4W4wBtnJMeVdWXIVCU1y/9bdRkJA1igZeahWh2OrXa1SQxWUmlPje TIuW3ZUM19S+jrBNC3DNGNCJ7kR2hwYBBTmGpnexHVPr6GLllMAajvrK//fe48fJNl6G qKV8JKS+evmZ45f6duL4Qzvw/shZg0hwhtmx+RTuEFdW/QP3tzFEwD6kD7CiNV/PSNyD hAfh9TfHZkdbEu+bxVxQZL3YXYyKdz366t+CO17h9PkCb+03BT1eLX7OrOZeb7KofZ4q 8jph3QZap6aR/QUugEtJknXccRBqKcNgnLmSY3iRnARa5xPlmJVAdLMXR0BKU55ej2ft B/+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=SQ2Uwhj6FDqhZFG4Jra0608BEmKaZpqCAcRucXb8YWg=; b=g+QdZcvLRVFW81qJBCsYWAGLyYlSC3Jhr0/cD5hMdB8+0DptcdLRjGQbz2+sn2OAoT WvIjLWlDvxscUeQkbda+tST/xdq1al7JzHqcslDWspMpFzAID2mjORz1sH3u0V+piQK2 JYuGCBagyTOEvszfCMeR/kt+YJEzFIjZaW/tynM+zynIT4NcIVBL34zogN7eshYA23JA dEN61+drA/M5bk5y5VLdpEXBjNztbYCea5ZUR/7fPlf3YwJ1xIQjWjAC2kUr6BqpTPKh YAiR0Yx+/ykVSECJVKyJskyznolvwo9GZwjgXU1e80qi71/wepkO1Y1wY1rWA+E1WbWE X7Bw== X-Gm-Message-State: AOAM533tzYKa+YJZ4PmVjwHY/h8/fE9xsJDQg9Rr7fc3fhqv3fsr7E+5 DNrh7gL/Cmsp0mywFPBTtl6KvGOt4fy21uRIEbD5cQ== X-Received: by 2002:a92:cb0f:: with SMTP id s15mr21046449ilo.59.1629702911172; Mon, 23 Aug 2021 00:15:11 -0700 (PDT) MIME-Version: 1.0 References: <20210816075449.2236547-1-kyletso@google.com> <05b01a2e-b1ee-4111-2e3c-897990544c0a@roeck-us.net> In-Reply-To: <05b01a2e-b1ee-4111-2e3c-897990544c0a@roeck-us.net> From: Kyle Tso Date: Mon, 23 Aug 2021 15:14:55 +0800 Message-ID: Subject: Re: [PATCH] usb: typec: tcpm: Raise vdm_sm_running flag only when VDM SM is running To: Guenter Roeck Cc: heikki.krogerus@linux.intel.com, gregkh@linuxfoundation.org, badhri@google.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 18, 2021 at 10:17 PM Guenter Roeck wrote: > > On 8/16/21 12:54 AM, Kyle Tso wrote: > > If the port is going to send Discover_Identity Message, vdm_sm_running > > flag was intentionally set before entering Ready States in order to > > avoid the conflict because the port and the port partner might start > > AMS at almost the same time after entering Ready States. > > > > However, the original design has a problem. When the port is doing > > DR_SWAP from Device to Host, it raises the flag. Later in the > > tcpm_send_discover_work, the flag blocks the procedure of sending the > > Discover_Identity and it might never be cleared until disconnection. > > > > Since there exists another flag send_discover representing that the port > > is going to send Discover_Identity or not, it is enough to use that flag > > to prevent the conflict. Also change the timing of the set/clear of > > vdm_sm_running to indicate whether the VDM SM is actually running or > > not. > > > > Fixes: c34e85fa69b9 ("usb: typec: tcpm: Send DISCOVER_IDENTITY from dedicated work") > > Cc: Badhri Jagan Sridharan > > Signed-off-by: Kyle Tso > > Reviewed-by: Guenter Roeck > Hi Greg, Do I need to modify something for this patch? thanks, Kyle > > --- > > drivers/usb/typec/tcpm/tcpm.c | 81 ++++++++++++++++------------------- > > 1 file changed, 38 insertions(+), 43 deletions(-) > > > > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c > > index 5b22a1c931a9..c05ddfbaff08 100644 > > --- a/drivers/usb/typec/tcpm/tcpm.c > > +++ b/drivers/usb/typec/tcpm/tcpm.c > > @@ -341,6 +341,7 @@ struct tcpm_port { > > bool vbus_source; > > bool vbus_charge; > > > > + /* Set to true when Discover_Identity Command is expected to be sent in Ready states. */ > > bool send_discover; > > bool op_vsafe5v; > > > > @@ -370,6 +371,7 @@ struct tcpm_port { > > struct hrtimer send_discover_timer; > > struct kthread_work send_discover_work; > > bool state_machine_running; > > + /* Set to true when VDM State Machine has following actions. */ > > bool vdm_sm_running; > > > > struct completion tx_complete; > > @@ -1431,6 +1433,7 @@ static void tcpm_queue_vdm(struct tcpm_port *port, const u32 header, > > /* Set ready, vdm state machine will actually send */ > > port->vdm_retries = 0; > > port->vdm_state = VDM_STATE_READY; > > + port->vdm_sm_running = true; > > > > mod_vdm_delayed_work(port, 0); > > } > > @@ -1673,7 +1676,6 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev, > > rlen = 1; > > } else { > > tcpm_register_partner_altmodes(port); > > - port->vdm_sm_running = false; > > } > > break; > > case CMD_ENTER_MODE: > > @@ -1721,14 +1723,12 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev, > > (VDO_SVDM_VERS(svdm_version)); > > break; > > } > > - port->vdm_sm_running = false; > > break; > > default: > > response[0] = p[0] | VDO_CMDT(CMDT_RSP_NAK); > > rlen = 1; > > response[0] = (response[0] & ~VDO_SVDM_VERS_MASK) | > > (VDO_SVDM_VERS(svdm_version)); > > - port->vdm_sm_running = false; > > break; > > } > > > > @@ -1765,6 +1765,20 @@ static void tcpm_handle_vdm_request(struct tcpm_port *port, > > } > > > > if (PD_VDO_SVDM(p[0])) { > > + /* > > + * Here a SVDM is received (INIT or RSP or unknown). Set the vdm_sm_running in > > + * advance because we are dropping the lock but may send VDMs soon. > > + * For the cases of INIT received: > > + * - If no response to send, it will be cleared later in this function. > > + * - If there are responses to send, it will be cleared in the state machine. > > + * For the cases of RSP received: > > + * - If no further INIT to send, it will be cleared later in this function. > > + * - Otherwise, it will be cleared in the state machine if timeout or it will go > > + * back here until no further INIT to send. > > + * For the cases of unknown type received: > > + * - We will send NAK and the flag will be cleared in the state machine. > > + */ > > + port->vdm_sm_running = true; > > rlen = tcpm_pd_svdm(port, adev, p, cnt, response, &adev_action); > > } else { > > if (port->negotiated_rev >= PD_REV30) > > @@ -1833,6 +1847,8 @@ static void tcpm_handle_vdm_request(struct tcpm_port *port, > > > > if (rlen > 0) > > tcpm_queue_vdm(port, response[0], &response[1], rlen - 1); > > + else > > + port->vdm_sm_running = false; > > } > > > > static void tcpm_send_vdm(struct tcpm_port *port, u32 vid, int cmd, > > @@ -1898,8 +1914,10 @@ static void vdm_run_state_machine(struct tcpm_port *port) > > * if there's traffic or we're not in PDO ready state don't send > > * a VDM. > > */ > > - if (port->state != SRC_READY && port->state != SNK_READY) > > + if (port->state != SRC_READY && port->state != SNK_READY) { > > + port->vdm_sm_running = false; > > break; > > + } > > > > /* TODO: AMS operation for Unstructured VDM */ > > if (PD_VDO_SVDM(vdo_hdr) && PD_VDO_CMDT(vdo_hdr) == CMDT_INIT) { > > @@ -2555,10 +2573,6 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, > > TYPEC_PWR_MODE_PD, > > port->pps_data.active, > > port->supply_voltage); > > - /* Set VDM running flag ASAP */ > > - if (port->data_role == TYPEC_HOST && > > - port->send_discover) > > - port->vdm_sm_running = true; > > tcpm_set_state(port, SNK_READY, 0); > > } else { > > /* > > @@ -2596,14 +2610,10 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, > > switch (port->state) { > > case SNK_NEGOTIATE_CAPABILITIES: > > /* USB PD specification, Figure 8-43 */ > > - if (port->explicit_contract) { > > + if (port->explicit_contract) > > next_state = SNK_READY; > > - if (port->data_role == TYPEC_HOST && > > - port->send_discover) > > - port->vdm_sm_running = true; > > - } else { > > + else > > next_state = SNK_WAIT_CAPABILITIES; > > - } > > > > /* Threshold was relaxed before sending Request. Restore it back. */ > > tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_PD, > > @@ -2618,10 +2628,6 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, > > port->pps_status = (type == PD_CTRL_WAIT ? > > -EAGAIN : -EOPNOTSUPP); > > > > - if (port->data_role == TYPEC_HOST && > > - port->send_discover) > > - port->vdm_sm_running = true; > > - > > /* Threshold was relaxed before sending Request. Restore it back. */ > > tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_PD, > > port->pps_data.active, > > @@ -2697,10 +2703,6 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, > > } > > break; > > case DR_SWAP_SEND: > > - if (port->data_role == TYPEC_DEVICE && > > - port->send_discover) > > - port->vdm_sm_running = true; > > - > > tcpm_set_state(port, DR_SWAP_CHANGE_DR, 0); > > break; > > case PR_SWAP_SEND: > > @@ -2738,7 +2740,7 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, > > PD_MSG_CTRL_NOT_SUPP, > > NONE_AMS); > > } else { > > - if (port->vdm_sm_running) { > > + if (port->send_discover) { > > tcpm_queue_message(port, PD_MSG_CTRL_WAIT); > > break; > > } > > @@ -2754,7 +2756,7 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, > > PD_MSG_CTRL_NOT_SUPP, > > NONE_AMS); > > } else { > > - if (port->vdm_sm_running) { > > + if (port->send_discover) { > > tcpm_queue_message(port, PD_MSG_CTRL_WAIT); > > break; > > } > > @@ -2763,7 +2765,7 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, > > } > > break; > > case PD_CTRL_VCONN_SWAP: > > - if (port->vdm_sm_running) { > > + if (port->send_discover) { > > tcpm_queue_message(port, PD_MSG_CTRL_WAIT); > > break; > > } > > @@ -4479,18 +4481,20 @@ static void run_state_machine(struct tcpm_port *port) > > /* DR_Swap states */ > > case DR_SWAP_SEND: > > tcpm_pd_send_control(port, PD_CTRL_DR_SWAP); > > + 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); > > - /* Set VDM state machine running flag ASAP */ > > - if (port->data_role == TYPEC_DEVICE && port->send_discover) > > - port->vdm_sm_running = true; > > + 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); > > break; > > case DR_SWAP_SEND_TIMEOUT: > > tcpm_swap_complete(port, -ETIMEDOUT); > > + port->send_discover = false; > > tcpm_ams_finish(port); > > tcpm_set_state(port, ready_state(port), 0); > > break; > > @@ -4502,7 +4506,6 @@ static void run_state_machine(struct tcpm_port *port) > > } else { > > tcpm_set_roles(port, true, port->pwr_role, > > TYPEC_HOST); > > - port->send_discover = true; > > } > > tcpm_ams_finish(port); > > tcpm_set_state(port, ready_state(port), 0); > > @@ -4645,8 +4648,6 @@ static void run_state_machine(struct tcpm_port *port) > > break; > > case VCONN_SWAP_SEND_TIMEOUT: > > tcpm_swap_complete(port, -ETIMEDOUT); > > - if (port->data_role == TYPEC_HOST && port->send_discover) > > - port->vdm_sm_running = true; > > tcpm_set_state(port, ready_state(port), 0); > > break; > > case VCONN_SWAP_START: > > @@ -4662,14 +4663,10 @@ static void run_state_machine(struct tcpm_port *port) > > case VCONN_SWAP_TURN_ON_VCONN: > > tcpm_set_vconn(port, true); > > tcpm_pd_send_control(port, PD_CTRL_PS_RDY); > > - if (port->data_role == TYPEC_HOST && port->send_discover) > > - port->vdm_sm_running = true; > > tcpm_set_state(port, ready_state(port), 0); > > break; > > case VCONN_SWAP_TURN_OFF_VCONN: > > tcpm_set_vconn(port, false); > > - if (port->data_role == TYPEC_HOST && port->send_discover) > > - port->vdm_sm_running = true; > > tcpm_set_state(port, ready_state(port), 0); > > break; > > > > @@ -4677,8 +4674,6 @@ static void run_state_machine(struct tcpm_port *port) > > case PR_SWAP_CANCEL: > > case VCONN_SWAP_CANCEL: > > tcpm_swap_complete(port, port->swap_status); > > - if (port->data_role == TYPEC_HOST && port->send_discover) > > - port->vdm_sm_running = true; > > if (port->pwr_role == TYPEC_SOURCE) > > tcpm_set_state(port, SRC_READY, 0); > > else > > @@ -5028,9 +5023,6 @@ static void _tcpm_pd_vbus_on(struct tcpm_port *port) > > switch (port->state) { > > case SNK_TRANSITION_SINK_VBUS: > > port->explicit_contract = true; > > - /* Set the VDM flag ASAP */ > > - if (port->data_role == TYPEC_HOST && port->send_discover) > > - port->vdm_sm_running = true; > > tcpm_set_state(port, SNK_READY, 0); > > break; > > case SNK_DISCOVERY: > > @@ -5425,15 +5417,18 @@ static void tcpm_send_discover_work(struct kthread_work *work) > > if (!port->send_discover) > > goto unlock; > > > > + if (port->data_role == TYPEC_DEVICE && port->negotiated_rev < PD_REV30) { > > + port->send_discover = false; > > + goto unlock; > > + } > > + > > /* Retry if the port is not idle */ > > if ((port->state != SRC_READY && port->state != SNK_READY) || port->vdm_sm_running) { > > mod_send_discover_delayed_work(port, SEND_DISCOVER_RETRY_MS); > > goto unlock; > > } > > > > - /* Only send the Message if the port is host for PD rev2.0 */ > > - if (port->data_role == TYPEC_HOST || port->negotiated_rev > PD_REV20) > > - tcpm_send_vdm(port, USB_SID_PD, CMD_DISCOVER_IDENT, NULL, 0); > > + tcpm_send_vdm(port, USB_SID_PD, CMD_DISCOVER_IDENT, NULL, 0); > > > > unlock: > > mutex_unlock(&port->lock); > > >