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=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 B4AABC433E9 for ; Tue, 26 Jan 2021 16:39:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 88E9A229C9 for ; Tue, 26 Jan 2021 16:39:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390712AbhAZI5X (ORCPT ); Tue, 26 Jan 2021 03:57:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:33404 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730047AbhAYSqR (ORCPT ); Mon, 25 Jan 2021 13:46:17 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 73F0922D58; Mon, 25 Jan 2021 18:45:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1611600344; bh=UKDr5wvYWa3oDVHqw81KBDA1tJIdeyCpvj3hgKXAwtg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wclE6nT0ickn82xmdWx1+UsIsNQRF44kGciOLkhVWTUD6DuCYiyUwNW9gQ6qUGAFL fMaSHcs7iVNrgLFtw7VOtihgOg/vUQUxl/8Bc7llWscWRCpl6WAyUgUXXvitUrdpKW fCcKYrq9NkDwiG5aO7ht6oN85TFqjE63UvtM7FWA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, JC Kuo , Mathias Nyman Subject: [PATCH 5.4 65/86] xhci: tegra: Delay for disabling LFPS detector Date: Mon, 25 Jan 2021 19:39:47 +0100 Message-Id: <20210125183203.792881184@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210125183201.024962206@linuxfoundation.org> References: <20210125183201.024962206@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 @@ -562,6 +562,13 @@ 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) {