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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87C42C433EF for ; Mon, 24 Jan 2022 19:41:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354985AbiAXTjq (ORCPT ); Mon, 24 Jan 2022 14:39:46 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:59736 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347352AbiAXTeY (ORCPT ); Mon, 24 Jan 2022 14:34:24 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 54F3060917; Mon, 24 Jan 2022 19:34:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A362C340E5; Mon, 24 Jan 2022 19:34:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643052863; bh=6+NvI3D2ofS6tpLj8IEjhMlFMf0PyRxXKA/Z7sc6oR8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wW09XfjEhMqBl+MMMmVeKHbGzWyCoGrFSVMnI7OszdpdPNnptXKo/wFVzuiUoqiqL Rs4v3ST175j1GQ4XyHRXZMRAMEzknggpmF0zmh702jan9Vm41MWZjVoESIzkWUlGb6 1tS7MBcuVDZVN89gakeFQUKZR+cTydsPki4xwBxo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alan Stern , Kai-Heng Feng , Sasha Levin Subject: [PATCH 5.4 197/320] usb: hub: Add delay for SuperSpeed hub resume to let links transit to U0 Date: Mon, 24 Jan 2022 19:43:01 +0100 Message-Id: <20220124184000.335031832@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124183953.750177707@linuxfoundation.org> References: <20220124183953.750177707@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kai-Heng Feng [ Upstream commit 00558586382891540c59c9febc671062425a6e47 ] When a new USB device gets plugged to nested hubs, the affected hub, which connects to usb 2-1.4-port2, doesn't report there's any change, hence the nested hubs go back to runtime suspend like nothing happened: [ 281.032951] usb usb2: usb wakeup-resume [ 281.032959] usb usb2: usb auto-resume [ 281.032974] hub 2-0:1.0: hub_resume [ 281.033011] usb usb2-port1: status 0263 change 0000 [ 281.033077] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000 [ 281.049797] usb 2-1: usb wakeup-resume [ 281.069800] usb 2-1: Waited 0ms for CONNECT [ 281.069810] usb 2-1: finish resume [ 281.070026] hub 2-1:1.0: hub_resume [ 281.070250] usb 2-1-port4: status 0203 change 0000 [ 281.070272] usb usb2-port1: resume, status 0 [ 281.070282] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000 [ 281.089813] usb 2-1.4: usb wakeup-resume [ 281.109792] usb 2-1.4: Waited 0ms for CONNECT [ 281.109801] usb 2-1.4: finish resume [ 281.109991] hub 2-1.4:1.0: hub_resume [ 281.110147] usb 2-1.4-port2: status 0263 change 0000 [ 281.110234] usb 2-1-port4: resume, status 0 [ 281.110239] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s [ 281.110266] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000 [ 281.110426] hub 2-1.4:1.0: hub_suspend [ 281.110565] usb 2-1.4: usb auto-suspend, wakeup 1 [ 281.130998] hub 2-1:1.0: hub_suspend [ 281.137788] usb 2-1: usb auto-suspend, wakeup 1 [ 281.142935] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000 [ 281.177828] usb 2-1: usb wakeup-resume [ 281.197839] usb 2-1: Waited 0ms for CONNECT [ 281.197850] usb 2-1: finish resume [ 281.197984] hub 2-1:1.0: hub_resume [ 281.198203] usb 2-1-port4: status 0203 change 0000 [ 281.198228] usb usb2-port1: resume, status 0 [ 281.198237] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000 [ 281.217835] usb 2-1.4: usb wakeup-resume [ 281.237834] usb 2-1.4: Waited 0ms for CONNECT [ 281.237845] usb 2-1.4: finish resume [ 281.237990] hub 2-1.4:1.0: hub_resume [ 281.238067] usb 2-1.4-port2: status 0263 change 0000 [ 281.238148] usb 2-1-port4: resume, status 0 [ 281.238152] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s [ 281.238166] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000 [ 281.238385] hub 2-1.4:1.0: hub_suspend [ 281.238523] usb 2-1.4: usb auto-suspend, wakeup 1 [ 281.258076] hub 2-1:1.0: hub_suspend [ 281.265744] usb 2-1: usb auto-suspend, wakeup 1 [ 281.285976] hub 2-0:1.0: hub_suspend [ 281.285988] usb usb2: bus auto-suspend, wakeup 1 USB 3.2 spec, 9.2.5.4 "Changing Function Suspend State" says that "If the link is in a non-U0 state, then the device must transition the link to U0 prior to sending the remote wake message", but the hub only transits the link to U0 after signaling remote wakeup. So be more forgiving and use a 20ms delay to let the link transit to U0 for remote wakeup. Suggested-by: Alan Stern Acked-by: Alan Stern Signed-off-by: Kai-Heng Feng Link: https://lore.kernel.org/r/20211215120108.336597-1-kai.heng.feng@canonical.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/core/hub.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 69dd48f9507e5..4cf0dc7f330dd 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1108,7 +1108,10 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type) } else { hub_power_on(hub, true); } - } + /* Give some time on remote wakeup to let links to transit to U0 */ + } else if (hub_is_superspeed(hub->hdev)) + msleep(20); + init2: /* -- 2.34.1