From patchwork Mon May 31 13:14:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 451228 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 17F17C4708F for ; Mon, 31 May 2021 13:38:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F070361960 for ; Mon, 31 May 2021 13:38:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231860AbhEaNkI (ORCPT ); Mon, 31 May 2021 09:40:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:44088 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232277AbhEaNh0 (ORCPT ); Mon, 31 May 2021 09:37:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 42B7E613C1; Mon, 31 May 2021 13:26:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1622467571; bh=kNsR7JH7HUPqnQDYu7+mJD6fvOY6gA/unXCy4XOe1RU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uQdh1sTLKIrMD0kOp1OAbD6m9g1zp2p2/AWRIjoT8AnipqrtzK1Yi+1F17jVcoDbI 0vMh2JAhjH2PfdHt8ObkqW6k07ng8zZD0xgdycvz7CmU7c0X8Bu4JoSkrtaPBa7Od0 jCSmVKA4YaHanxoQVtfoLCFirCXVcERX+g8kN/pw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alan Stern , Chunfeng Yun Subject: [PATCH 4.19 116/116] usb: core: reduce power-on-good delay time of root hub Date: Mon, 31 May 2021 15:14:52 +0200 Message-Id: <20210531130644.055697545@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210531130640.131924542@linuxfoundation.org> References: <20210531130640.131924542@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chunfeng Yun commit 90d28fb53d4a51299ff324dede015d5cb11b88a2 upstream. Return the exactly delay time given by root hub descriptor, this helps to reduce resume time etc. Due to the root hub descriptor is usually provided by the host controller driver, if there is compatibility for a root hub, we can fix it easily without affect other root hub Acked-by: Alan Stern Signed-off-by: Chunfeng Yun Link: https://lore.kernel.org/r/1618017645-12259-1-git-send-email-chunfeng.yun@mediatek.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/usb/core/hub.h +++ b/drivers/usb/core/hub.h @@ -146,8 +146,10 @@ static inline unsigned hub_power_on_good { unsigned delay = hub->descriptor->bPwrOn2PwrGood * 2; - /* Wait at least 100 msec for power to become stable */ - return max(delay, 100U); + if (!hub->hdev->parent) /* root hub */ + return delay; + else /* Wait at least 100 msec for power to become stable */ + return max(delay, 100U); } static inline int hub_port_debounce_be_connected(struct usb_hub *hub,