From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A917C433E1 for ; Tue, 11 Aug 2020 18:24:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4364120781 for ; Tue, 11 Aug 2020 18:24:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="kVR4/Hh2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726154AbgHKSYs (ORCPT ); Tue, 11 Aug 2020 14:24:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58896 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725987AbgHKSYp (ORCPT ); Tue, 11 Aug 2020 14:24:45 -0400 Received: from mail-vs1-xe42.google.com (mail-vs1-xe42.google.com [IPv6:2607:f8b0:4864:20::e42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BED8C061787 for ; Tue, 11 Aug 2020 11:24:45 -0700 (PDT) Received: by mail-vs1-xe42.google.com with SMTP id j23so6488400vsq.7 for ; Tue, 11 Aug 2020 11:24:44 -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=0bbVhUdfyZzfrQXbmgWLydmB0LBLARZ5TVy9YQKsgx0=; b=kVR4/Hh27NyUuG4f8zGbtHJDgMKzkYr2Wfjris9a177lbJBd4SK9pY856sHOYHjlWF Ii1LXNVWskF7E3g5gYF7IysgSqB0IdrbpHcA0g8ZeYeoqhbS0X5ntXYytrjdUE33WkQ+ r39kXpLAm1oLmp1Zs/FSUv3RAPju9OzNldQ03V4QHJ64DHyrwNRRFs+W5CK6gDZbzp/S 5J+NOL3B1jGJ1ITwOm2O5zm5djiqWwgXdQzspvef2O9sWENrGDcAoABWVyLeHE6ZCt8j /Kc0IgHdy+pkhUYr+eGVA5MPedWpqUlTaUzH7hRJdC/Tzey9goPXn3iorqn0MiYU6mDK n+hQ== 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=0bbVhUdfyZzfrQXbmgWLydmB0LBLARZ5TVy9YQKsgx0=; b=ohRXB2ERGcvjTzl/WNpF+xh+19yCFsr7fK49fIkfHKacZYmYPWiKEEkDXHzpcesXI3 roOOdOiQsyzbnRpP838d4Nj3zz73InZx9e1bVj7SStH3iIjT1ZQRi6DG7t7CJB/4WOq0 7NK2BRFqj0NiTJVbdGdy9mm+aVloihEpyHK4Ni5EJN44kA/SfMbwXdu0z28y2L8Ggo1X yfXewPpIQQmz+eqjVJ384+50VCFLDh86JTB6icxXgaJX667LeD15mcyWz0Kz4GYQKZjn FsJu4amNGrmGjlC8gbU/YYDV+eUV+delJiJRrDRLs1TccGiquktj4Y5GKP6msCrVzfd+ am1A== X-Gm-Message-State: AOAM532RAKLeZZpPVQKV8gL9UCV0iy0lEV0U4VizoEhw9NECgDTMmtgX sCB7ycrleolCzn0NE9wH7CYiGs5DuPEMQaruw1PNe3hnWSY= X-Google-Smtp-Source: ABdhPJyPdoWdzJvqIUBhLpZ2m3/RQ9sPpDgddJNs05BtKbWqMfhfIx6cyGW42JKuVd7/Hs/mRFPk3B+ha+RzscTvclg= X-Received: by 2002:a67:fbd1:: with SMTP id o17mr24263853vsr.19.1597170283940; Tue, 11 Aug 2020 11:24:43 -0700 (PDT) MIME-Version: 1.0 References: <20200811011126.130297-1-badhri@google.com> In-Reply-To: From: Badhri Jagan Sridharan Date: Tue, 11 Aug 2020 11:24:07 -0700 Message-ID: Subject: Re: [PATCH v1] usb: typec: tcpm: Fix TDA 2.2.1.1 and TDA 2.2.1.2 failures To: Guenter Roeck Cc: Heikki Krogerus , Greg Kroah-Hartman , USB , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Mon, Aug 10, 2020 at 6:51 PM Guenter Roeck wrote: > > On 8/10/20 6:11 PM, Badhri Jagan Sridharan wrote: > >>From the spec: > > "7.1.5 Response to Hard Resets > > Hard Reset Signaling indicates a communication failure has occurred and > > the Source Shall stop driving VCONN, Shall remove Rp from the VCONN pin > > and Shall drive VBUS to vSafe0V as shown in Figure 7-9. The USB connection > > May reset during a Hard Reset since the VBUS voltage will be less than > > vSafe5V for an extended period of time. After establishing the vSafe0V > > voltage condition on VBUS, the Source Shall wait tSrcRecover before > > re-applying VCONN and restoring VBUS to vSafe5V. A Source Shall conform > > to the VCONN timing as specified in [USB Type-C 1.3]." > > > > Signed-off-by: Badhri Jagan Sridharan > > --- > > drivers/usb/typec/tcpm/tcpm.c | 16 +++++++++++++--- > > 1 file changed, 13 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c > > index 3ef37202ee37..e41c4e5d3c71 100644 > > --- a/drivers/usb/typec/tcpm/tcpm.c > > +++ b/drivers/usb/typec/tcpm/tcpm.c > > @@ -3372,13 +3372,19 @@ static void run_state_machine(struct tcpm_port *port) > > tcpm_set_state(port, SNK_HARD_RESET_SINK_OFF, 0); > > break; > > case SRC_HARD_RESET_VBUS_OFF: > > - tcpm_set_vconn(port, true); > > + /* > > + * 7.1.5 Response to Hard Resets > > + * Hard Reset Signaling indicates a communication failure has occurred and the > > + * Source Shall stop driving VCONN, Shall remove Rp from the VCONN pin and Shall > > + * drive VBUS to vSafe0V as shown in Figure 7-9. > > + */ > > + tcpm_set_vconn(port, false); > > tcpm_set_vbus(port, false); > > tcpm_set_roles(port, port->self_powered, TYPEC_SOURCE, > > tcpm_data_role_for_source(port)); > > - tcpm_set_state(port, SRC_HARD_RESET_VBUS_ON, PD_T_SRC_RECOVER); > > I am a bit concerned about this. If I understand correctly, it means that > we won't turn VBUS back on unless a SRC_HARD_RESET_VBUS_OFF PD event is received. > Is that correct ? What happens if that event is never received ? > > Thanks, > Guenter The term PD event is a little ambiguous to me. Trying to summarize the workflow. Lower level tcpc driver would have to call tcpm_vbus_change which would in-turn trigger TCPM_VBUS_EVENT and queries port->tcpc->get_vbus to get the vbus status. It is not really a PD protocol driven event hence the confusion. "What happens if that event is never received ?" Yeah TCPM would be in SRC_HARD_RESET_VBUS_OFF till the tcpc calls the tcpm_vbus_change. Do you suspect that existing tcpc would not have the capability to monitor vbus status while sourcing and call tcpm_vbus_change? Thanks, Badhri > > break; > > case SRC_HARD_RESET_VBUS_ON: > > + tcpm_set_vconn(port, true); > > tcpm_set_vbus(port, true); > > port->tcpc->set_pd_rx(port->tcpc, true); > > tcpm_set_attached_state(port, true); > > @@ -3944,7 +3950,11 @@ static void _tcpm_pd_vbus_off(struct tcpm_port *port) > > tcpm_set_state(port, SNK_HARD_RESET_WAIT_VBUS, 0); > > break; > > case SRC_HARD_RESET_VBUS_OFF: > > - tcpm_set_state(port, SRC_HARD_RESET_VBUS_ON, 0); > > + /* > > + * After establishing the vSafe0V voltage condition on VBUS, the Source Shall wait > > + * tSrcRecover before re-applying VCONN and restoring VBUS to vSafe5V. > > + */ > > + tcpm_set_state(port, SRC_HARD_RESET_VBUS_ON, PD_T_SRC_RECOVER); > > break; > > case HARD_RESET_SEND: > > break; > > >