From patchwork Fri Nov 26 03:26:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Kai-Heng Feng X-Patchwork-Id: 517777 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 82C74C433F5 for ; Fri, 26 Nov 2021 03:29:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243339AbhKZDc0 (ORCPT ); Thu, 25 Nov 2021 22:32:26 -0500 Received: from smtp-relay-canonical-1.canonical.com ([185.125.188.121]:44650 "EHLO smtp-relay-canonical-1.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230304AbhKZDa0 (ORCPT ); Thu, 25 Nov 2021 22:30:26 -0500 Received: from localhost.localdomain (unknown [10.101.196.174]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-1.canonical.com (Postfix) with ESMTPSA id A5D3D41DF6; Fri, 26 Nov 2021 03:27:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1637897232; bh=vHP6c9N8j5OhKGnWFmc24lI/KclLdUnZPq6vHBJtGvk=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version:Content-Type; b=F52AU9mnbkPXhC5oRoU1NjNIjX4GNfDOcZ0gSzgJApbMv3q7C95oX9RIAxY4cOFiX RQTMy/YO95xV7bXwSqK/HLkaXg9G3C4VBUvFhgGlkIy++ePjILFxMMQF/6HKvkU1tu Haejln6y6O05pT+vFFY44AJMs3VeuEEIEIqSCsz43EOH+ODTKhUpLKO3a9GOdqRO7/ a3SbFySiBWF3HvI3RRAPmBqBd4OjuIIHWw6daMc4Zj1+ZhoLROsI4pS/E1QvOmItL0 noCm+dU4dT/AGUe/zJkU6jCmc5gclK8VNiIem4KBtoqMIhpQsFnfgf29sJGfPj+RTT WAyUsb+nHWn5Q== From: Kai-Heng Feng To: gregkh@linuxfoundation.org Cc: stern@rowland.harvard.edu, mathias.nyman@linux.intel.com, Kai-Heng Feng , Thinh Nguyen , Bixuan Cui , Andrew Lunn , Chris Chiu , Rajat Jain , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] usb: core: Avoid doing warm reset on disconnect event Date: Fri, 26 Nov 2021 11:26:21 +0800 Message-Id: <20211126032622.1101448-1-kai.heng.feng@canonical.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Unplugging USB device may cause an incorrect warm reset loop: [ 143.039019] xhci_hcd 0000:00:14.0: Port change event, 2-3, id 19, portsc: 0x4202c0 [ 143.039025] xhci_hcd 0000:00:14.0: handle_port_status: starting usb2 port polling. [ 143.039051] hub 2-0:1.0: state 7 ports 10 chg 0000 evt 0008 [ 143.039058] xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x4202c0, return 0x4102c0 [ 143.039092] xhci_hcd 0000:00:14.0: clear port3 connect change, portsc: 0x4002c0 [ 143.039096] usb usb2-port3: link state change [ 143.039099] xhci_hcd 0000:00:14.0: clear port3 link state change, portsc: 0x2c0 [ 143.039101] usb usb2-port3: do warm reset [ 143.096736] xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2b0, return 0x2b0 [ 143.096751] usb usb2-port3: not warm reset yet, waiting 50ms [ 143.131500] xhci_hcd 0000:00:14.0: Can't queue urb, port error, link inactive [ 143.138260] xhci_hcd 0000:00:14.0: Port change event, 2-3, id 19, portsc: 0x2802a0 [ 143.138263] xhci_hcd 0000:00:14.0: handle_port_status: starting usb2 port polling. [ 143.160756] xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2802a0, return 0x3002a0 [ 143.160798] usb usb2-port3: not warm reset yet, waiting 200ms The warm reset is due to its PLS is in eSS.Inactive state. However, USB 3.2 spec table 10-13 mentions "Ports can be disabled by either a fault condition (disconnect event or other fault condition)", xHCI 1.2 spec table 5-27 also states that "This flag shall automatically be cleared to ‘0’ by a disconnect event or other fault condition." on PED. So use CSC = 0 and PED = 0 as indication that device is disconnecting to avoid doing warm reset. Signed-off-by: Kai-Heng Feng --- drivers/usb/core/hub.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 86658a81d2844..abd5a83d194b0 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -5530,6 +5530,7 @@ static void port_event(struct usb_hub *hub, int port1) __must_hold(&port_dev->status_lock) { int connect_change; + int disconnect = 0; struct usb_port *port_dev = hub->ports[port1 - 1]; struct usb_device *udev = port_dev->child; struct usb_device *hdev = hub->hdev; @@ -5545,6 +5546,9 @@ static void port_event(struct usb_hub *hub, int port1) if (portchange & USB_PORT_STAT_C_CONNECTION) { usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION); connect_change = 1; + if (!(portstatus & USB_PORT_STAT_CONNECTION) && + !(portstatus & USB_PORT_STAT_ENABLE)) + disconnect = 1; } if (portchange & USB_PORT_STAT_C_ENABLE) { @@ -5613,7 +5617,7 @@ static void port_event(struct usb_hub *hub, int port1) * Warm reset a USB3 protocol port if it's in * SS.Inactive state. */ - if (hub_port_warm_reset_required(hub, port1, portstatus)) { + if (hub_port_warm_reset_required(hub, port1, portstatus) && !disconnect) { dev_dbg(&port_dev->dev, "do warm reset\n"); if (!udev || !(portstatus & USB_PORT_STAT_CONNECTION) || udev->state == USB_STATE_NOTATTACHED) {