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=-18.8 required=3.0 tests=BAYES_00,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 7127BC433DB for ; Tue, 26 Jan 2021 08:26:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 378D2221FD for ; Tue, 26 Jan 2021 08:26:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389047AbhAZI0f (ORCPT ); Tue, 26 Jan 2021 03:26:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:58352 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727648AbhAYSms (ORCPT ); Mon, 25 Jan 2021 13:42:48 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id EFCB923104; Mon, 25 Jan 2021 18:42:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1611600127; bh=0lY4H3kBTeH0lr7fN7Qyk/PF6JGXFxRNxZtQMOKWVSI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bmi2aZQscteBTg53xnA0g4BWSafQtj8+YbEtFR1FucpGJMYDOjnhEYSgelIU83MYo Jleq5f/WftMeMZtSi2VqnMhDKV0GsizWdN7exsktiY0u//2CcksVRlF101cgVa5ITO eMkeYBFLseBhHbUaM7OC5xB+zcZ6+OvJowMVKMbc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, JC Kuo , Mathias Nyman Subject: [PATCH 4.19 42/58] xhci: tegra: Delay for disabling LFPS detector Date: Mon, 25 Jan 2021 19:39:43 +0100 Message-Id: <20210125183158.527649766@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210125183156.702907356@linuxfoundation.org> References: <20210125183156.702907356@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: linux-kernel@vger.kernel.org From: JC Kuo commit da7e0c3c2909a3d9bf8acfe1db3cb213bd7febfb upstream. Occasionally, we are seeing some SuperSpeed devices resumes right after being directed to U3. This commits add 500us delay to ensure LFPS detector is disabled before sending ACK to firmware. [ 16.099363] tegra-xusb 70090000.usb: entering ELPG [ 16.104343] tegra-xusb 70090000.usb: 2-1 isn't suspended: 0x0c001203 [ 16.114576] tegra-xusb 70090000.usb: not all ports suspended: -16 [ 16.120789] tegra-xusb 70090000.usb: entering ELPG failed The register write passes through a few flop stages of 32KHz clock domain. NVIDIA ASIC designer reviewed RTL and suggests 500us delay. Cc: stable@vger.kernel.org Signed-off-by: JC Kuo Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20210115161907.2875631-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-tegra.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/usb/host/xhci-tegra.c +++ b/drivers/usb/host/xhci-tegra.c @@ -578,6 +578,13 @@ static void tegra_xusb_mbox_handle(struc enable); if (err < 0) break; + + /* + * wait 500us for LFPS detector to be disabled before + * sending ACK + */ + if (!enable) + usleep_range(500, 1000); } if (err < 0) {