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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 26FA5C433E9 for ; Wed, 23 Dec 2020 03:11:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F22B3207AA for ; Wed, 23 Dec 2020 03:11:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728043AbgLWDKc (ORCPT ); Tue, 22 Dec 2020 22:10:32 -0500 Received: from mail.kernel.org ([198.145.29.99]:45490 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728019AbgLWCS0 (ORCPT ); Tue, 22 Dec 2020 21:18:26 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8A7DB23340; Wed, 23 Dec 2020 02:17:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1608689842; bh=IrQRczZ1434DC/p28wgC7GQZrA0bAQYAf1NcxjIhvcU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OSEmmks7SbeaLwa2xy1Ry9R1UhXudU1i6X0S1W10hVSy/GTfxWLRs8eIi7ls+1mWh tN5c/OjMu0KhAIfR6W5sl2GdFPruVVrLBQsqIj4AWfQk/qyoziiFZCnHcveiPAtPax mK1lJMAptsEQuQuFZ3yJzHecu2k2dpk7THve9BC08Fsk0yyVmrj7JHa03DhwIvfR72 NZJhGjpeiQJj2NCx+yBVHcpBkYZOnjwKSwzEVF18gKBZIfUmgPlJlLn7Dx50atfsot ehc7fTl/fu3UgP4SxZbYkinyfHaHpDXqjabOrAryNCQyjgesS//c1QQ/3LP5qMuHAU VjqB45ee1+hcQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Benjamin Berg , Hans de Goede , Heikki Krogerus , Greg Kroah-Hartman , Sasha Levin , linux-usb@vger.kernel.org Subject: [PATCH AUTOSEL 5.10 042/217] usb: typec: ucsi: Work around PPM losing change information Date: Tue, 22 Dec 2020 21:13:31 -0500 Message-Id: <20201223021626.2790791-42-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201223021626.2790791-1-sashal@kernel.org> References: <20201223021626.2790791-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Benjamin Berg [ Upstream commit 217504a055325fe76ec1142aa15f14d3db77f94f ] Some/many PPMs are simply clearing the change bitfield when a notification on a port is acknowledge. Unfortunately, doing so means that any changes between the GET_CONNECTOR_STATUS and ACK_CC_CI commands is simply lost. Work around this by re-fetching the connector status afterwards. We can then infer any changes that we see have happened but that may not be respresented in the change bitfield. We end up with the following actions: 1. UCSI_GET_CONNECTOR_STATUS, store result, update unprocessed_changes 2. UCSI_GET_CAM_SUPPORTED, discard result 3. ACK connector change 4. UCSI_GET_CONNECTOR_STATUS, store result 5. Infere lost changes by comparing UCSI_GET_CONNECTOR_STATUS results 6. If PPM reported a new change, then restart in order to ACK 7. Process everything as usual. The worker is also changed to re-schedule itself if a new change notification happened while it was running. Doing this fixes quite commonly occurring issues where e.g. the UCSI power supply would remain online even thought the ThunderBolt cable was unplugged. Cc: Hans de Goede Cc: Heikki Krogerus Acked-by: Heikki Krogerus Signed-off-by: Benjamin Berg Link: https://lore.kernel.org/r/20201009144047.505957-3-benjamin@sipsolutions.net Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/typec/ucsi/ucsi.c | 125 ++++++++++++++++++++++++++++------ drivers/usb/typec/ucsi/ucsi.h | 2 + 2 files changed, 107 insertions(+), 20 deletions(-) diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index 51a570d40a42e..f02958927cbd8 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -53,7 +53,7 @@ static int ucsi_acknowledge_connector_change(struct ucsi *ucsi) ctrl = UCSI_ACK_CC_CI; ctrl |= UCSI_ACK_CONNECTOR_CHANGE; - return ucsi->ops->async_write(ucsi, UCSI_CONTROL, &ctrl, sizeof(ctrl)); + return ucsi->ops->sync_write(ucsi, UCSI_CONTROL, &ctrl, sizeof(ctrl)); } static int ucsi_exec_command(struct ucsi *ucsi, u64 command); @@ -625,21 +625,113 @@ static void ucsi_handle_connector_change(struct work_struct *work) struct ucsi_connector *con = container_of(work, struct ucsi_connector, work); struct ucsi *ucsi = con->ucsi; + struct ucsi_connector_status pre_ack_status; + struct ucsi_connector_status post_ack_status; enum typec_role role; + u16 inferred_changes; + u16 changed_flags; u64 command; int ret; mutex_lock(&con->lock); + /* + * Some/many PPMs have an issue where all fields in the change bitfield + * are cleared when an ACK is send. This will causes any change + * between GET_CONNECTOR_STATUS and ACK to be lost. + * + * We work around this by re-fetching the connector status afterwards. + * We then infer any changes that we see have happened but that may not + * be represented in the change bitfield. + * + * Also, even though we don't need to know the currently supported alt + * modes, we run the GET_CAM_SUPPORTED command to ensure the PPM does + * not get stuck in case it assumes we do. + * Always do this, rather than relying on UCSI_CONSTAT_CAM_CHANGE to be + * set in the change bitfield. + * + * We end up with the following actions: + * 1. UCSI_GET_CONNECTOR_STATUS, store result, update unprocessed_changes + * 2. UCSI_GET_CAM_SUPPORTED, discard result + * 3. ACK connector change + * 4. UCSI_GET_CONNECTOR_STATUS, store result + * 5. Infere lost changes by comparing UCSI_GET_CONNECTOR_STATUS results + * 6. If PPM reported a new change, then restart in order to ACK + * 7. Process everything as usual. + * + * We may end up seeing a change twice, but we can only miss extremely + * short transitional changes. + */ + + /* 1. First UCSI_GET_CONNECTOR_STATUS */ + command = UCSI_GET_CONNECTOR_STATUS | UCSI_CONNECTOR_NUMBER(con->num); + ret = ucsi_send_command(ucsi, command, &pre_ack_status, + sizeof(pre_ack_status)); + if (ret < 0) { + dev_err(ucsi->dev, "%s: GET_CONNECTOR_STATUS failed (%d)\n", + __func__, ret); + goto out_unlock; + } + con->unprocessed_changes |= pre_ack_status.change; + + /* 2. Run UCSI_GET_CAM_SUPPORTED and discard the result. */ + command = UCSI_GET_CAM_SUPPORTED; + command |= UCSI_CONNECTOR_NUMBER(con->num); + ucsi_send_command(con->ucsi, command, NULL, 0); + + /* 3. ACK connector change */ + clear_bit(EVENT_PENDING, &ucsi->flags); + ret = ucsi_acknowledge_connector_change(ucsi); + if (ret) { + dev_err(ucsi->dev, "%s: ACK failed (%d)", __func__, ret); + goto out_unlock; + } + + /* 4. Second UCSI_GET_CONNECTOR_STATUS */ command = UCSI_GET_CONNECTOR_STATUS | UCSI_CONNECTOR_NUMBER(con->num); - ret = ucsi_send_command(ucsi, command, &con->status, - sizeof(con->status)); + ret = ucsi_send_command(ucsi, command, &post_ack_status, + sizeof(post_ack_status)); if (ret < 0) { dev_err(ucsi->dev, "%s: GET_CONNECTOR_STATUS failed (%d)\n", __func__, ret); goto out_unlock; } + /* 5. Inferre any missing changes */ + changed_flags = pre_ack_status.flags ^ post_ack_status.flags; + inferred_changes = 0; + if (UCSI_CONSTAT_PWR_OPMODE(changed_flags) != 0) + inferred_changes |= UCSI_CONSTAT_POWER_OPMODE_CHANGE; + + if (changed_flags & UCSI_CONSTAT_CONNECTED) + inferred_changes |= UCSI_CONSTAT_CONNECT_CHANGE; + + if (changed_flags & UCSI_CONSTAT_PWR_DIR) + inferred_changes |= UCSI_CONSTAT_POWER_DIR_CHANGE; + + if (UCSI_CONSTAT_PARTNER_FLAGS(changed_flags) != 0) + inferred_changes |= UCSI_CONSTAT_PARTNER_CHANGE; + + if (UCSI_CONSTAT_PARTNER_TYPE(changed_flags) != 0) + inferred_changes |= UCSI_CONSTAT_PARTNER_CHANGE; + + /* Mask out anything that was correctly notified in the later call. */ + inferred_changes &= ~post_ack_status.change; + if (inferred_changes) + dev_dbg(ucsi->dev, "%s: Inferred changes that would have been lost: 0x%04x\n", + __func__, inferred_changes); + + con->unprocessed_changes |= inferred_changes; + + /* 6. If PPM reported a new change, then restart in order to ACK */ + if (post_ack_status.change) + goto out_unlock; + + /* 7. Continue as if nothing happened */ + con->status = post_ack_status; + con->status.change = con->unprocessed_changes; + con->unprocessed_changes = 0; + role = !!(con->status.flags & UCSI_CONSTAT_PWR_DIR); if (con->status.change & UCSI_CONSTAT_POWER_OPMODE_CHANGE || @@ -680,28 +772,19 @@ static void ucsi_handle_connector_change(struct work_struct *work) ucsi_port_psy_changed(con); } - if (con->status.change & UCSI_CONSTAT_CAM_CHANGE) { - /* - * We don't need to know the currently supported alt modes here. - * Running GET_CAM_SUPPORTED command just to make sure the PPM - * does not get stuck in case it assumes we do so. - */ - command = UCSI_GET_CAM_SUPPORTED; - command |= UCSI_CONNECTOR_NUMBER(con->num); - ucsi_send_command(con->ucsi, command, NULL, 0); - } - if (con->status.change & UCSI_CONSTAT_PARTNER_CHANGE) ucsi_partner_change(con); - ret = ucsi_acknowledge_connector_change(ucsi); - if (ret) - dev_err(ucsi->dev, "%s: ACK failed (%d)", __func__, ret); - trace_ucsi_connector_change(con->num, &con->status); out_unlock: - clear_bit(EVENT_PENDING, &ucsi->flags); + if (test_and_clear_bit(EVENT_PENDING, &ucsi->flags)) { + schedule_work(&con->work); + mutex_unlock(&con->lock); + return; + } + + clear_bit(EVENT_PROCESSING, &ucsi->flags); mutex_unlock(&con->lock); } @@ -719,7 +802,9 @@ void ucsi_connector_change(struct ucsi *ucsi, u8 num) return; } - if (!test_and_set_bit(EVENT_PENDING, &ucsi->flags)) + set_bit(EVENT_PENDING, &ucsi->flags); + + if (!test_and_set_bit(EVENT_PROCESSING, &ucsi->flags)) schedule_work(&con->work); } EXPORT_SYMBOL_GPL(ucsi_connector_change); diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h index b7a92f2460507..dd9ba60ab4a30 100644 --- a/drivers/usb/typec/ucsi/ucsi.h +++ b/drivers/usb/typec/ucsi/ucsi.h @@ -296,6 +296,7 @@ struct ucsi { #define EVENT_PENDING 0 #define COMMAND_PENDING 1 #define ACK_PENDING 2 +#define EVENT_PROCESSING 3 }; #define UCSI_MAX_SVID 5 @@ -322,6 +323,7 @@ struct ucsi_connector { struct typec_capability typec_cap; + u16 unprocessed_changes; struct ucsi_connector_status status; struct ucsi_connector_capability cap; struct power_supply *psy; -- 2.27.0