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=-6.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED 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 42D88C43387 for ; Mon, 17 Dec 2018 02:57:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0808120883 for ; Mon, 17 Dec 2018 02:57:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="MBq8oCIJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731323AbeLQC5P (ORCPT ); Sun, 16 Dec 2018 21:57:15 -0500 Received: from mail-pg1-f195.google.com ([209.85.215.195]:41136 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726267AbeLQC5P (ORCPT ); Sun, 16 Dec 2018 21:57:15 -0500 Received: by mail-pg1-f195.google.com with SMTP id m1so3741195pgq.8; Sun, 16 Dec 2018 18:57:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=rc8gPXiQqLn156m1XReqA2cndEyaq3ICkIfja/vtcAA=; b=MBq8oCIJajUnP0C7M34UnSI5a5p1GzjH9TG7iXcH8ARzdCxqHNS4lRVEyyApnvOmAZ WphCnkOKnuXMYmfC9uXLhJuP4n4rSbOFbHSNXTGI+IItIEypNX0A+YwUwkmoS9NOBHTe jLMcbTzgGboR5YRyHFSLAOcGofAajSotWxMnt4WXzceFGdEITFO8BKhyQJ+BI1IGHl+L PF9UWOPqTqX/eOi+GLDedqZWsFUCE2/AoxYG41s4gA19H31JiMvdeUWhZhhabHt0e/Ml SVko1mEtEn6jPPeL60Jzqam+aq3b4y+SsnmhN7vF9c1mVaVyEzpb2VEuJ6M+p+Ef7CAQ q/6Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:subject:to:cc:references:from:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=rc8gPXiQqLn156m1XReqA2cndEyaq3ICkIfja/vtcAA=; b=AFh47MiaPuZz47bjr6R4w4iTihcPm7G9+vZQiQNHZr/iSgT8bwIT3I7Z0jF0kPI4tq mAFvHOwyBCSGSJapF4xglkxl5n6QPRiVAORv6LdBVk2EvIGOhrwuscKJuUrN4sbYjdmf pZI866/Le/9IcCrnazGFwVKh9YRCrq0uVnW71ue4hy3KZeidkjbL1HT3KHi78XJf3Qfn ICVEI0dFuj5NQVCFr23I9f4NYTZnCmMFVHDLZPBZ7sjdz10sNKS6jd3SEihnK27O6sb3 P8F06iO3AvM91O34OaJdQdIqhJY7JNO76KxZ7/vvEzKKXQI/NGDCDx7560niM/0qplGA zeZQ== X-Gm-Message-State: AA+aEWb2U8zs/8nPh+YRCvEBeqFqm8d59ncQw/BjYbgWbbUCroE5Ly5q lOsBwpUNmUyZdMj7nfNreaxHy+XN X-Google-Smtp-Source: AFSGD/VSC8B/GrQiufV0AGBhb4V0Ss3DrcMIPUMsPsynk8hnjftcmLSFNvANW2EMBMdTDGzXOshzuQ== X-Received: by 2002:a63:5f88:: with SMTP id t130mr10852046pgb.395.1545015433875; Sun, 16 Dec 2018 18:57:13 -0800 (PST) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id y89sm15338439pfa.136.2018.12.16.18.57.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 16 Dec 2018 18:57:12 -0800 (PST) Subject: Re: [PATCH] usb: typec: tcpm: Extend the matching rules on PPS APDO selection To: Kyle Tso , heikki.krogerus@linux.intel.com, gregkh@linuxfoundation.org, Adam.Thomson.Opensource@diasemi.com Cc: badhri@google.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org References: <20181217024805.122897-1-kyletso@google.com> From: Guenter Roeck Message-ID: <3f116158-d900-1dcd-387f-d8129a0f0dd0@roeck-us.net> Date: Sun, 16 Dec 2018 18:57:11 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <20181217024805.122897-1-kyletso@google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/16/18 6:48 PM, Kyle Tso wrote: > Current matching rules ensure that the voltage range of selected Source > Capability is entirely within the range defined in one of the Sink > Capabilities. This is reasonable but not practical because Sink may not > support wide range of voltage when sinking power while Source could > advertise its capabilities in raletively wider range. For example, a > Source PDO advertising 3.3V-11V@3A (9V Prog of Fixed Nominal Voltage) > will not be selected if the Sink requires 5V-12V@3A PPS power. However, > the Sink could work well if the requested voltage range in RDOs is > 5V-11V@3A. > > Currently accepted: > |--------- source -----| > |----------- sink ---------------| > > Currently not accepted: > |--------- source -----| > |----------- sink ---------------| > > |--------- source -----| > |----------- sink ---------------| > > |--------- source -----------------| > |------ sink -------| > > To improve the usability, change the matching rules to what listed > below: > a. The Source PDO is selectable if any portion of the voltage range > overlaps one of the Sink PDO's voltage range. > b. The maximum operational voltage will be the lower one between the > selected Source PDO and the matching Sink PDO. > c. The maximum power will be the maximum operational voltage times the > maximum current defined in the selected Source PDO > d. Select the Source PDO with the highest maximum power > > Signed-off-by: Kyle Tso Reviewed-by: Guenter Roeck > > --- > Changelog since v1: > - updated the commit message as suggested by Guenter Roeck > --- > drivers/usb/typec/tcpm/tcpm.c | 29 +++++++++++++++++------------ > 1 file changed, 17 insertions(+), 12 deletions(-) > > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c > index 3620efee2688..3001df7bd602 100644 > --- a/drivers/usb/typec/tcpm/tcpm.c > +++ b/drivers/usb/typec/tcpm/tcpm.c > @@ -2213,7 +2213,8 @@ static unsigned int tcpm_pd_select_pps_apdo(struct tcpm_port *port) > unsigned int i, j, max_mw = 0, max_mv = 0; > unsigned int min_src_mv, max_src_mv, src_ma, src_mw; > unsigned int min_snk_mv, max_snk_mv; > - u32 pdo; > + unsigned int max_op_mv; > + u32 pdo, src, snk; > unsigned int src_pdo = 0, snk_pdo = 0; > > /* > @@ -2263,16 +2264,18 @@ static unsigned int tcpm_pd_select_pps_apdo(struct tcpm_port *port) > continue; > } > > - if (max_src_mv <= max_snk_mv && > - min_src_mv >= min_snk_mv) { > + if (min_src_mv <= max_snk_mv && > + max_src_mv >= min_snk_mv) { > + max_op_mv = min(max_src_mv, max_snk_mv); > + src_mw = (max_op_mv * src_ma) / 1000; > /* Prefer higher voltages if available */ > if ((src_mw == max_mw && > - min_src_mv > max_mv) || > + max_op_mv > max_mv) || > src_mw > max_mw) { > src_pdo = i; > snk_pdo = j; > max_mw = src_mw; > - max_mv = max_src_mv; > + max_mv = max_op_mv; > } > } > } > @@ -2285,14 +2288,16 @@ static unsigned int tcpm_pd_select_pps_apdo(struct tcpm_port *port) > } > > if (src_pdo) { > - pdo = port->source_caps[src_pdo]; > - > - port->pps_data.min_volt = pdo_pps_apdo_min_voltage(pdo); > - port->pps_data.max_volt = pdo_pps_apdo_max_voltage(pdo); > - port->pps_data.max_curr = > - min_pps_apdo_current(pdo, port->snk_pdo[snk_pdo]); > + src = port->source_caps[src_pdo]; > + snk = port->snk_pdo[snk_pdo]; > + > + port->pps_data.min_volt = max(pdo_pps_apdo_min_voltage(src), > + pdo_pps_apdo_min_voltage(snk)); > + port->pps_data.max_volt = min(pdo_pps_apdo_max_voltage(src), > + pdo_pps_apdo_max_voltage(snk)); > + port->pps_data.max_curr = min_pps_apdo_current(src, snk); > port->pps_data.out_volt = > - min(pdo_pps_apdo_max_voltage(pdo), port->pps_data.out_volt); > + min(port->pps_data.max_volt, port->pps_data.out_volt); > port->pps_data.op_curr = > min(port->pps_data.max_curr, port->pps_data.op_curr); > } >