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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 66E7AC41514 for ; Fri, 2 Aug 2019 09:47:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E0122086A for ; Fri, 2 Aug 2019 09:47:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564739234; bh=k1DdW9q4s8i60smQGx86EQOHfoeowZDWDTC7zIaE1fw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZpCncFJdF3Rq1UqzAYuUGPQg1ni/jAIh/IgHSPEidaLXFHJ8LTVTFkKRfPiX+9HRE crablgtwB4NBtav+nzm2s+DHpik+nFvxYv7n4iACFOU+Nb8Yxpg4kzzkG+cf/2rqAi /H/X+O6myW2kmSb1OJnuU3LxcMQEI2oNZI523rTs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405652AbfHBJrN (ORCPT ); Fri, 2 Aug 2019 05:47:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:51874 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405639AbfHBJrK (ORCPT ); Fri, 2 Aug 2019 05:47:10 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B397E206A2; Fri, 2 Aug 2019 09:47:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564739229; bh=k1DdW9q4s8i60smQGx86EQOHfoeowZDWDTC7zIaE1fw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1FRVMptV33tSBJMERmbxeJmlZxtWDmsSJ+ALggpVv4TLJ4/u4Um+4qGitbjw6UplF SckDleV86oSdfsb30VJG6iXWqwJhAum1w7mWJfr7jScyD8aWxMuYqO1WebTvCM7SYI EpPeV/tYuMAMO0Nh4yOceh5yhzkskJLAdg5jllr8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thinh Nguyen , Sasha Levin Subject: [PATCH 4.9 160/223] usb: core: hub: Disable hub-initiated U1/U2 Date: Fri, 2 Aug 2019 11:36:25 +0200 Message-Id: <20190802092248.588783817@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190802092238.692035242@linuxfoundation.org> References: <20190802092238.692035242@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit 561759292774707b71ee61aecc07724905bb7ef1 ] If the device rejects the control transfer to enable device-initiated U1/U2 entry, then the device will not initiate U1/U2 transition. To improve the performance, the downstream port should not initate transition to U1/U2 to avoid the delay from the device link command response (no packet can be transmitted while waiting for a response from the device). If the device has some quirks and does not implement U1/U2, it may reject all the link state change requests, and the downstream port may resend and flood the bus with more requests. This will affect the device performance even further. This patch disables the hub-initated U1/U2 if the device-initiated U1/U2 entry fails. Reference: USB 3.2 spec 7.2.4.2.3 Signed-off-by: Thinh Nguyen Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/core/hub.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 9f132fac7b2c..63646dc3ca27 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -3879,6 +3879,9 @@ static int usb_set_lpm_timeout(struct usb_device *udev, * control transfers to set the hub timeout or enable device-initiated U1/U2 * will be successful. * + * If the control transfer to enable device-initiated U1/U2 entry fails, then + * hub-initiated U1/U2 will be disabled. + * * If we cannot set the parent hub U1/U2 timeout, we attempt to let the xHCI * driver know about it. If that call fails, it should be harmless, and just * take up more slightly more bus bandwidth for unnecessary U1/U2 exit latency. @@ -3933,23 +3936,24 @@ static void usb_enable_link_state(struct usb_hcd *hcd, struct usb_device *udev, * host know that this link state won't be enabled. */ hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state); - } else { - /* Only a configured device will accept the Set Feature - * U1/U2_ENABLE - */ - if (udev->actconfig) - usb_set_device_initiated_lpm(udev, state, true); + return; + } - /* As soon as usb_set_lpm_timeout(timeout) returns 0, the - * hub-initiated LPM is enabled. Thus, LPM is enabled no - * matter the result of usb_set_device_initiated_lpm(). - * The only difference is whether device is able to initiate - * LPM. - */ + /* Only a configured device will accept the Set Feature + * U1/U2_ENABLE + */ + if (udev->actconfig && + usb_set_device_initiated_lpm(udev, state, true) == 0) { if (state == USB3_LPM_U1) udev->usb3_lpm_u1_enabled = 1; else if (state == USB3_LPM_U2) udev->usb3_lpm_u2_enabled = 1; + } else { + /* Don't request U1/U2 entry if the device + * cannot transition to U1/U2. + */ + usb_set_lpm_timeout(udev, state, 0); + hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state); } } -- 2.20.1