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=-7.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, URIBL_SBL,URIBL_SBL_A,USER_AGENT_MUTT autolearn=ham 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 78FD7C65C22 for ; Fri, 2 Nov 2018 13:28:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 496A12081B for ; Fri, 2 Nov 2018 13:28:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 496A12081B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727650AbeKBWfg (ORCPT ); Fri, 2 Nov 2018 18:35:36 -0400 Received: from mga11.intel.com ([192.55.52.93]:9525 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726026AbeKBWfg (ORCPT ); Fri, 2 Nov 2018 18:35:36 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Nov 2018 06:28:26 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,456,1534834800"; d="scan'208";a="104738329" Received: from kuha.fi.intel.com ([10.237.72.189]) by fmsmga001.fm.intel.com with SMTP; 02 Nov 2018 06:28:22 -0700 Received: by kuha.fi.intel.com (sSMTP sendmail emulation); Fri, 02 Nov 2018 15:28:21 +0200 Date: Fri, 2 Nov 2018 15:28:21 +0200 From: Heikki Krogerus To: Badhri Jagan Sridharan Cc: Rob Herring , Mark Rutland , Greg Kroah-Hartman , Chanwoo Choi , Andrzej Hajda , Li Jun , linux@roeck-us.net, jackp@codeaurora.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: [PATCH v3 2/3] usb: typec: tcpm: Do not disconnect link for self powered devices Message-ID: <20181102132821.GB6543@kuha.fi.intel.com> References: <20181001194501.58338-1-badhri@google.com> <20181001194501.58338-2-badhri@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181001194501.58338-2-badhri@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 01, 2018 at 12:45:00PM -0700, Badhri Jagan Sridharan wrote: > During HARD_RESET the data link is disconnected. > For self powered device, the spec is advising against doing that. > > >From USB_PD_R3_0 > 7.1.5 Response to Hard Resets > Device operation during and after a Hard Reset is defined as follows: > Self-powered devices Should Not disconnect from USB during a Hard Reset > (see Section 9.1.2). > Bus powered devices will disconnect from USB during a Hard Reset due to the > loss of their power source. > > Tackle this by letting TCPM know whether the device is self or bus powered. > > This overcomes unnecessary port disconnections from hard reset. > Also, speeds up the enumeration time when connected to Type-A ports. > > Signed-off-by: Badhri Jagan Sridharan Reviewed-by: Heikki Krogerus > --------- > Version history: > V3: > Rebase on top of usb-next > > V2: > Based on feedback from heikki.krogerus@linux.intel.com > - self_powered added to the struct tcpm_port which is populated from > a. "connector" node of the device tree in tcpm_fw_get_caps() > b. "self_powered" node of the tcpc_config in tcpm_copy_caps > > Based on feedbase from linux@roeck-us.net > - Code was refactored > - SRC_HARD_RESET_VBUS_OFF sets the link state to false based > on self_powered flag > > V1 located here: > https://lkml.org/lkml/2018/9/13/94 > --- > drivers/usb/typec/tcpm/tcpm.c | 12 ++++++++++-- > include/linux/usb/tcpm.h | 1 + > 2 files changed, 11 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c > index 4f1f4215f3d6..c3ac0e46106b 100644 > --- a/drivers/usb/typec/tcpm/tcpm.c > +++ b/drivers/usb/typec/tcpm/tcpm.c > @@ -317,6 +317,9 @@ struct tcpm_port { > /* Deadline in jiffies to exit src_try_wait state */ > unsigned long max_wait; > > + /* port belongs to a self powered device */ > + bool self_powered; > + > #ifdef CONFIG_DEBUG_FS > struct dentry *dentry; > struct mutex logbuffer_lock; /* log buffer access lock */ > @@ -3257,7 +3260,8 @@ static void run_state_machine(struct tcpm_port *port) > case SRC_HARD_RESET_VBUS_OFF: > tcpm_set_vconn(port, true); > tcpm_set_vbus(port, false); > - tcpm_set_roles(port, false, TYPEC_SOURCE, TYPEC_HOST); > + tcpm_set_roles(port, port->self_powered, TYPEC_SOURCE, > + TYPEC_HOST); > tcpm_set_state(port, SRC_HARD_RESET_VBUS_ON, PD_T_SRC_RECOVER); > break; > case SRC_HARD_RESET_VBUS_ON: > @@ -3270,7 +3274,8 @@ static void run_state_machine(struct tcpm_port *port) > memset(&port->pps_data, 0, sizeof(port->pps_data)); > tcpm_set_vconn(port, false); > tcpm_set_charge(port, false); > - tcpm_set_roles(port, false, TYPEC_SINK, TYPEC_DEVICE); > + tcpm_set_roles(port, port->self_powered, TYPEC_SINK, > + TYPEC_DEVICE); > /* > * VBUS may or may not toggle, depending on the adapter. > * If it doesn't toggle, transition to SNK_HARD_RESET_SINK_ON > @@ -4409,6 +4414,8 @@ static int tcpm_fw_get_caps(struct tcpm_port *port, > return -EINVAL; > port->operating_snk_mw = mw / 1000; > > + port->self_powered = fwnode_property_read_bool(fwnode, "self-powered"); > + > return 0; > } > > @@ -4717,6 +4724,7 @@ static int tcpm_copy_caps(struct tcpm_port *port, > port->typec_caps.prefer_role = tcfg->default_role; > port->typec_caps.type = tcfg->type; > port->typec_caps.data = tcfg->data; > + port->self_powered = port->tcpc->config->self_powered; > > return 0; > } > diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h > index 7e7fbfb84e8e..50c74a77db55 100644 > --- a/include/linux/usb/tcpm.h > +++ b/include/linux/usb/tcpm.h > @@ -89,6 +89,7 @@ struct tcpc_config { > enum typec_port_data data; > enum typec_role default_role; > bool try_role_hw; /* try.{src,snk} implemented in hardware */ > + bool self_powered; /* port belongs to a self powered device */ > > const struct typec_altmode_desc *alt_modes; > }; > -- > 2.19.0.605.g01d371f741-goog thanks, -- heikki