From patchwork Fri Nov 29 17:41:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kai-Heng Feng X-Patchwork-Id: 11267445 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2709D14B7 for ; Fri, 29 Nov 2019 17:41:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 099872158A for ; Fri, 29 Nov 2019 17:41:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727086AbfK2Rl1 (ORCPT ); Fri, 29 Nov 2019 12:41:27 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:52169 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726970AbfK2Rl1 (ORCPT ); Fri, 29 Nov 2019 12:41:27 -0500 Received: from 61-220-137-37.hinet-ip.hinet.net ([61.220.137.37] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1iakGi-0005XR-JC; Fri, 29 Nov 2019 17:41:25 +0000 From: Kai-Heng Feng To: gregkh@linuxfoundation.org Cc: stern@rowland.harvard.edu, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Kai-Heng Feng Subject: [PATCH v2 2/2] USB: core: Attempt power cycle port when it's in eSS.Disabled state Date: Sat, 30 Nov 2019 01:41:15 +0800 Message-Id: <20191129174115.31683-2-kai.heng.feng@canonical.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191129174115.31683-1-kai.heng.feng@canonical.com> References: <20191129174115.31683-1-kai.heng.feng@canonical.com> Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Dell TB16, Realtek USB ethernet (r8152) connects to an SMSC hub which then connects to ASMedia xHCI's root hub: /: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 5000M |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/7p, 5000M |__ Port 2: Dev 3, If 0, Class=Vendor Specific Class, Driver=r8152, 5000M Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 004 Device 002: ID 0424:5537 Standard Microsystems Corp. USB5537B Bus 004 Device 003: ID 0bda:8153 Realtek Semiconductor Corp. RTL8153 Gigabit Ethernet Adapter The SMSC hub may disconnect after system resume from suspend. When this happens, the reset resume attempt fails, and the last resort to disable the port and see something comes up later, also fails. When the issue occurs, the link state stays in eSS.Disabled state despite the warm reset attempts. Accoding to spec this can be caused by invalid VBus, after some expiremets, the SMSC hub can be brought back after a powercycle. So let's power cycle the port at the end of reset resume attempt, if it's in eSS.Disabled state. Signed-off-by: Kai-Heng Feng --- v2: - Lower dev_info() to dev_dbg(). drivers/usb/core/hub.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 6b6cd76ac5e6..a2e6001046f5 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2739,6 +2739,18 @@ static bool hub_port_warm_reset_required(struct usb_hub *hub, int port1, || link_state == USB_SS_PORT_LS_COMP_MOD; } +static bool hub_port_power_cycle_required(struct usb_hub *hub, int port1, + u16 portstatus) +{ + u16 link_state; + + if (!hub_is_superspeed(hub->hdev)) + return false; + + link_state = portstatus & USB_PORT_STAT_LINK_STATE; + return link_state == USB_SS_PORT_LS_SS_DISABLED; +} + static void hub_port_power_cycle(struct usb_hub *hub, int port1) { struct usb_port *port_dev = hub->ports[port1 - 1]; @@ -3601,6 +3613,10 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg) if (status < 0) { dev_dbg(&udev->dev, "can't resume, status %d\n", status); hub_port_logical_disconnect(hub, port1); + if (hub_port_power_cycle_required(hub, port1, portstatus)) { + dev_dbg(&udev->dev, "device in disabled state, attempt power cycle\n"); + hub_port_power_cycle(hub, port1); + } } else { /* Try to enable USB2 hardware LPM */ usb_enable_usb2_hardware_lpm(udev);