From patchwork Wed Jun 16 09:01:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kyle Tso X-Patchwork-Id: 462653 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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT, 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 2028AC48BE5 for ; Wed, 16 Jun 2021 09:01:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EED876128B for ; Wed, 16 Jun 2021 09:01:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231524AbhFPJDS (ORCPT ); Wed, 16 Jun 2021 05:03:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231513AbhFPJDR (ORCPT ); Wed, 16 Jun 2021 05:03:17 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95640C061574 for ; Wed, 16 Jun 2021 02:01:11 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id e78-20020a25d3510000b029054f20395eddso1547218ybf.13 for ; Wed, 16 Jun 2021 02:01:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=3M0UKlv9SOpLXUL9qCPgM2BG4Do5o9apkVkW/TG2GZY=; b=XUUaWCKmiuW4vDogg4QoHBx8qvu2ygQ5gyuUydllq4h5NX0BZFN3ZgFb/opCPL9Haq JWmayPho/GZFgz9Da110xPx/UXrlBT/2W80DWm3Lb8pmJ0ODrvmwwwRmPVEF/2XuLb+E sJImWCIX0ilq5YpZFF1sRelBfRbtaOlp30NwzxS1BwxWOazp3oZGGxBKJR8F+/rrv6dy 2bsAvAVWCAXPDokwd7GHCN+4rRJLH4qOMXEan6oF8RrxSaTv0wm7OimbmFCtvHHvTWxY 9oEAshM/jUwG3Mfi4n7EluXJhOXsl4KY7JAIsTfypH9Et8TubFZwwLGdxGGKCcQPk0JR YNbw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=3M0UKlv9SOpLXUL9qCPgM2BG4Do5o9apkVkW/TG2GZY=; b=EYxu1a0Utu22MHyn2ZNltqK5rMYIUWmfob6Thpj8yxKhHxgIOwGTQ+0z+Hrmzn/Rmz t4PpMIcM0Q6h4WF1Sy+oj5FIpDiGD+HdhiGFfMKbPzXYTcmq4sqY+FowDM3zF6jm4mnu MrVfbK424kEmNwo+kd5+bE8JK6JUTBS9s5n7C5GtN8lmA9nfbn6pgrgZ1t1SW7Z+i3x3 tu+E2UDVm+8FrI1dCn8nRo2p8seXkEXZQ1YTw20kG11uN26J3TVotaO+MRrLxgdpZoFr wkjHe3NkLX5j6/cFIroJNA14/olFG5yC5Pu+8x7Rm3MRVZ0QTLzNP0iW1VCwuPl21Dgi SPvA== X-Gm-Message-State: AOAM532XszBIY96cAk44fqcFTHV4xu0gFpKa4Ry559Ed659yQAnPpJQy Ue+OUbtWSDV7J8FTVDKGVhOvzUml/9Zw X-Google-Smtp-Source: ABdhPJwng0J1nrvO5rVrzAydm5TO3Oi6kIALs3pguNbRP6QqiQuA2oZhFG6nu3vAmNLpZ4Br5VgOMwi/Ic6Q X-Received: from kyletso.ntc.corp.google.com ([2401:fa00:fc:202:490b:5c68:72a5:d6d7]) (user=kyletso job=sendgmr) by 2002:a25:9bc4:: with SMTP id w4mr4516910ybo.168.1623834067902; Wed, 16 Jun 2021 02:01:07 -0700 (PDT) Date: Wed, 16 Jun 2021 17:01:02 +0800 Message-Id: <20210616090102.1897674-1-kyletso@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.32.0.272.g935e593368-goog Subject: [PATCH v3] usb: typec: tcpm: Relax disconnect threshold during power negotiation From: Kyle Tso To: linux@roeck-us.net, heikki.krogerus@linux.intel.com, gregkh@linuxfoundation.org Cc: badhri@google.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Kyle Tso Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org If the voltage is being decreased in power negotiation, the Source will set the power supply to operate at the new voltage level before sending PS_RDY. Relax the threshold before sending Request Message so that it will not race with Source which begins to adjust the voltage right after it sends Accept Message (PPS) or tSrcTransition (25~35ms) after it sends Accept Message (non-PPS). The real threshold will be set after Sink receives PS_RDY Message. Fixes: f321a02caebd ("usb: typec: tcpm: Implement enabling Auto Discharge disconnect support") Cc: Badhri Jagan Sridharan Signed-off-by: Kyle Tso Reviewed-by: Badhri Jagan Sridharan --- Changes in v3: - move the timing of setting threshold for Fixed RDO as I did for PPS in v2, i.e. move it to tcpm_pd_send_request. - add Cc: tag for Badhri - update the commit message for the above changes Changes in v2: - move the timing of setting threshold up to "before sending Request" for PPS power negotiation so that it won't race with the Source. - PPS: if it fails to send the Request, fallback to previous threshold - PPS: if the Source doesn't respond Accept, fallback to previous threshold - update the commit message for above changes drivers/usb/typec/tcpm/tcpm.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index 197556038ba4..b1d310ab84c4 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -2604,6 +2604,11 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, } 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, + port->pps_data.active, + port->supply_voltage); tcpm_set_state(port, next_state, 0); break; case SNK_NEGOTIATE_PPS_CAPABILITIES: @@ -2617,6 +2622,11 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, 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, + port->supply_voltage); + tcpm_set_state(port, SNK_READY, 0); break; case DR_SWAP_SEND: @@ -3336,6 +3346,12 @@ static int tcpm_pd_send_request(struct tcpm_port *port) if (ret < 0) return ret; + /* + * Relax the threshold as voltage will be adjusted after Accept Message plus tSrcTransition. + * It is safer to modify the threshold here. + */ + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, 0); + memset(&msg, 0, sizeof(msg)); msg.header = PD_HEADER_LE(PD_DATA_REQUEST, port->pwr_role, @@ -3433,6 +3449,9 @@ static int tcpm_pd_send_pps_request(struct tcpm_port *port) if (ret < 0) return ret; + /* Relax the threshold as voltage will be adjusted right after Accept Message. */ + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, 0); + memset(&msg, 0, sizeof(msg)); msg.header = PD_HEADER_LE(PD_DATA_REQUEST, port->pwr_role, @@ -4196,6 +4215,10 @@ static void run_state_machine(struct tcpm_port *port) port->hard_reset_count = 0; ret = tcpm_pd_send_request(port); if (ret < 0) { + /* Restore back to the original state */ + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_PD, + port->pps_data.active, + port->supply_voltage); /* Let the Source send capabilities again. */ tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0); } else { @@ -4206,6 +4229,10 @@ static void run_state_machine(struct tcpm_port *port) case SNK_NEGOTIATE_PPS_CAPABILITIES: ret = tcpm_pd_send_pps_request(port); if (ret < 0) { + /* Restore back to the original state */ + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_PD, + port->pps_data.active, + port->supply_voltage); port->pps_status = ret; /* * If this was called due to updates to sink