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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 F001CC433DF for ; Mon, 29 Jun 2020 22:00:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D06FE2078A for ; Mon, 29 Jun 2020 22:00:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593468050; bh=gdqGbviJQ8DPHxHnkuoAUnXO84jNZ/sdL4M8a2yZTZg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dJS7h8IvLhu9p5pL31G1siHL1CZdEVDY0JlpILgUBsyUMAP7MsS8QymIF8DxZmCQO IdaKzGInrO4bjPxDpctlktdJwyPPwm242kDRzjmuIjCQUfHl4V3LxraaGwT5NU6BC1 cDsTUY6Aod9QgzfUmnD5O0snMC/iaiwq4uaCzJfo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404833AbgF2WAs (ORCPT ); Mon, 29 Jun 2020 18:00:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:56796 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726334AbgF2SfY (ORCPT ); Mon, 29 Jun 2020 14:35:24 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6C35624640; Mon, 29 Jun 2020 15:19:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593443965; bh=gdqGbviJQ8DPHxHnkuoAUnXO84jNZ/sdL4M8a2yZTZg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cQBqF9oztiGjtZxlBcMptoZXgvkoIiJQc5iTDnIYyXVoxo7yM6oF0Ut/+OJjlOMxT sAiMf4rWBD1pSoX3tdTOhOrNd3zqc9iIBLVXdgF0Ek80i7Pjhu2vzwHZIZ6qU/S6y7 GuA5RPfryC52Dg7t1DpU+eDMmr+FqaXs88zMyCh0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kai-Heng Feng , Mathias Nyman , Greg Kroah-Hartman Subject: [PATCH 5.7 068/265] xhci: Poll for U0 after disabling USB2 LPM Date: Mon, 29 Jun 2020 11:15:01 -0400 Message-Id: <20200629151818.2493727-69-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200629151818.2493727-1-sashal@kernel.org> References: <20200629151818.2493727-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.7.7-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.7.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.7.7-rc1 X-KernelTest-Deadline: 2020-07-01T15:14+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kai-Heng Feng commit b3d71abd135e6919ca0b6cab463738472653ddfb upstream. USB2 devices with LPM enabled may interrupt the system suspend: [ 932.510475] usb 1-7: usb suspend, wakeup 0 [ 932.510549] hub 1-0:1.0: hub_suspend [ 932.510581] usb usb1: bus suspend, wakeup 0 [ 932.510590] xhci_hcd 0000:00:14.0: port 9 not suspended [ 932.510593] xhci_hcd 0000:00:14.0: port 8 not suspended .. [ 932.520323] xhci_hcd 0000:00:14.0: Port change event, 1-7, id 7, portsc: 0x400e03 .. [ 932.591405] PM: pci_pm_suspend(): hcd_pci_suspend+0x0/0x30 returns -16 [ 932.591414] PM: dpm_run_callback(): pci_pm_suspend+0x0/0x160 returns -16 [ 932.591418] PM: Device 0000:00:14.0 failed to suspend async: error -16 During system suspend, USB core will let HC suspends the device if it doesn't have remote wakeup enabled and doesn't have any children. However, from the log above we can see that the usb 1-7 doesn't get bus suspended due to not in U0. After a while the port finished U2 -> U0 transition, interrupts the suspend process. The observation is that after disabling LPM, port doesn't transit to U0 immediately and can linger in U2. xHCI spec 4.23.5.2 states that the maximum exit latency for USB2 LPM should be BESL + 10us. The BESL for the affected device is advertised as 400us, which is still not enough based on my testing result. So let's use the maximum permitted latency, 10000, to poll for U0 status to solve the issue. Cc: stable@vger.kernel.org Signed-off-by: Kai-Heng Feng Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20200624135949.22611-6-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index bee5deccc83d8..10d76205a79ca 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -4471,6 +4471,9 @@ static int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd, mutex_lock(hcd->bandwidth_mutex); xhci_change_max_exit_latency(xhci, udev, 0); mutex_unlock(hcd->bandwidth_mutex); + readl_poll_timeout(ports[port_num]->addr, pm_val, + (pm_val & PORT_PLS_MASK) == XDEV_U0, + 100, 10000); return 0; } } -- 2.25.1