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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 13158C433B4 for ; Thu, 8 Apr 2021 08:14:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CF2F8611C0 for ; Thu, 8 Apr 2021 08:14:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229895AbhDHIPD (ORCPT ); Thu, 8 Apr 2021 04:15:03 -0400 Received: from mga11.intel.com ([192.55.52.93]:58267 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229602AbhDHIPD (ORCPT ); Thu, 8 Apr 2021 04:15:03 -0400 IronPort-SDR: F2Aw8UckAUdvEIjlLV9a9ptijGXVFmrrIl9QaYO1S8mRdLu+jsk6voffgUJmANZd8qj+U4SXzR WTarAffj8R0w== X-IronPort-AV: E=McAfee;i="6000,8403,9947"; a="190282272" X-IronPort-AV: E=Sophos;i="5.82,205,1613462400"; d="scan'208";a="190282272" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Apr 2021 01:14:51 -0700 IronPort-SDR: u17QK3dbYDdv3YD21AwbvsHt3moRZAX13IaPNQsH177xWjg8kKQ/3GzoduKaGyAfWBNKdS12K0 HN7gy1CSOiBQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,205,1613462400"; d="scan'208";a="519762410" Received: from kuha.fi.intel.com ([10.237.72.162]) by fmsmga001.fm.intel.com with SMTP; 08 Apr 2021 01:14:47 -0700 Received: by kuha.fi.intel.com (sSMTP sendmail emulation); Thu, 08 Apr 2021 11:14:47 +0300 Date: Thu, 8 Apr 2021 11:14:47 +0300 From: Heikki Krogerus To: Badhri Jagan Sridharan Cc: Guenter Roeck , Greg Kroah-Hartman , Rob Herring , Adam Thomson , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Kyle Tso Subject: Re: [PATCH v2 5/6] usb: typec: tcpm: Allow slow charging loops to comply to pSnkStby Message-ID: References: <20210407200723.1914388-1-badhri@google.com> <20210407200723.1914388-5-badhri@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210407200723.1914388-5-badhri@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, Apr 07, 2021 at 01:07:22PM -0700, Badhri Jagan Sridharan wrote: > When a PD charger advertising Rp-3.0 is connected to a sink port, the > sink port current limit would 3A, during SNK_DISCOVERY, till power > negotiation starts. Once the negotiation starts the power limit needs > to drop down to pSnkStby(500mA @ 5V) and to negotiated current limit > once the explicit contract is in place. Not all charging loops can ramp > up to 3A and drop down to 500mA within tSnkStdby which is 15ms. The port > partner might hard reset if tSnkStdby is not met. > > To solve this problem, this patch introduces slow-charger-loop which > when set makes the port request PD_P_SNK_STDBY_MW upon entering > SNK_DISCOVERY(instead of 3A or the 1.5A during SNK_DISCOVERY) and the > actual currrent limit after RX of PD_CTRL_PSRDY for PD link or during > SNK_READY for non-pd link. > > Signed-off-by: Badhri Jagan Sridharan > --- > drivers/usb/typec/tcpm/tcpm.c | 18 +++++++++++++++--- > 1 file changed, 15 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c > index 770b2edd9a04..b5bed6866a2b 100644 > --- a/drivers/usb/typec/tcpm/tcpm.c > +++ b/drivers/usb/typec/tcpm/tcpm.c > @@ -459,6 +459,12 @@ struct tcpm_port { > /* Auto vbus discharge status */ > bool auto_vbus_discharge_enabled; > > + /* > + * When set, port requests PD_P_SNK_STDBY_MW upon entering SNK_DISCOVERY and > + * the actual currrent limit after RX of PD_CTRL_PSRDY for PD link, > + * SNK_READY for non-pd link. > + */ > + bool slow_charger_loop; > #ifdef CONFIG_DEBUG_FS > struct dentry *dentry; > struct mutex logbuffer_lock; /* log buffer access lock */ > @@ -4047,9 +4053,12 @@ static void run_state_machine(struct tcpm_port *port) > break; > case SNK_DISCOVERY: > if (port->vbus_present) { > - tcpm_set_current_limit(port, > - tcpm_get_current_limit(port), > - 5000); > + u32 current_lim = (!port->slow_charger_loop || > + (tcpm_get_current_limit(port) <= > + PD_P_SNK_STDBY_MW / 5)) ? > + tcpm_get_current_limit(port) : > + PD_P_SNK_STDBY_MW / 5; Here the use of the ternary operator is not appropriate. Please try to clean that up somehow. Maybe something like this would be better? u32 current_lim = tcpm_get_current_limit(port); if (port->slow_charger_loop || (current_lim < PD_P_SNK_STDBY_MW / 5)) current_lim = PD_P_SNK_STDBY_MW / 5; > + tcpm_set_current_limit(port, current_lim, 5000); > tcpm_set_charge(port, true); > tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0); > break; > @@ -4161,6 +4170,8 @@ static void run_state_machine(struct tcpm_port *port) > port->pwr_opmode = TYPEC_PWR_MODE_PD; > } > > + if (!port->pd_capable && port->slow_charger_loop) > + tcpm_set_current_limit(port, tcpm_get_current_limit(port), 5000); > tcpm_swap_complete(port, 0); > tcpm_typec_connect(port); > mod_enable_frs_delayed_work(port, 0); > @@ -5763,6 +5774,7 @@ static int tcpm_fw_get_caps(struct tcpm_port *port, > port->typec_caps.type = ret; > port->port_type = port->typec_caps.type; > > + port->slow_charger_loop = fwnode_property_read_bool(fwnode, "slow-charger-loop"); > if (port->port_type == TYPEC_PORT_SNK) > goto sink; > > -- > 2.31.1.295.g9ea45b61b8-goog thanks, -- heikki