From patchwork Sat Apr 10 01:20:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chunfeng Yun X-Patchwork-Id: 12195275 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 C2126C433B4 for ; Sat, 10 Apr 2021 01:21:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 869236115A for ; Sat, 10 Apr 2021 01:21:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235374AbhDJBV0 (ORCPT ); Fri, 9 Apr 2021 21:21:26 -0400 Received: from mailgw01.mediatek.com ([210.61.82.183]:43271 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S235215AbhDJBVZ (ORCPT ); Fri, 9 Apr 2021 21:21:25 -0400 X-UUID: 0552d5ee4a19427dba5c0f3cce0da988-20210410 X-UUID: 0552d5ee4a19427dba5c0f3cce0da988-20210410 Received: from mtkcas06.mediatek.inc [(172.21.101.30)] by mailgw01.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.14 Build 0819 with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 786209695; Sat, 10 Apr 2021 09:21:07 +0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs06n1.mediatek.inc (172.21.101.129) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Sat, 10 Apr 2021 09:21:06 +0800 Received: from localhost.localdomain (10.17.3.153) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Sat, 10 Apr 2021 09:21:05 +0800 From: Chunfeng Yun To: Greg Kroah-Hartman , Alan Stern CC: Matthias Brugger , Chunfeng Yun , Nishad Kamdar , , , , , Eddie Hung Subject: [PATCH v2] usb: core: reduce power-on-good delay time of root hub Date: Sat, 10 Apr 2021 09:20:45 +0800 Message-ID: <1618017645-12259-1-git-send-email-chunfeng.yun@mediatek.com> X-Mailer: git-send-email 1.8.1.1.dirty MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org 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 --- v2: remove RFC tag, and add acked-by Alan --- drivers/usb/core/hub.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h index 73f4482d833a..22ea1f4f2d66 100644 --- a/drivers/usb/core/hub.h +++ b/drivers/usb/core/hub.h @@ -148,8 +148,10 @@ static inline unsigned hub_power_on_good_delay(struct usb_hub *hub) { 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,