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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 DB200C43387 for ; Mon, 7 Jan 2019 16:16:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 98EF12173C for ; Mon, 7 Jan 2019 16:16:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546877784; bh=uWjSlrvkw39gqwOG51hP7wzxnSNcL9yvELOQZCSvFZs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=E4STfUeAYZgRSdcXrFbt8eSU6Su/E++bszPipOJ+meZWFX3/h9SCM3b0JwTaV+rms oBZ5gRpeqVXsTmNDN6Y/xp4aFhKdd0SfsxMZjiAfR013ujyMbc88z7L3m4tKhGpqnL uLk8qjY1E1Er3EnqHoNDL/FOWCa7xVA7rqeaYaK0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729445AbfAGQQX (ORCPT ); Mon, 7 Jan 2019 11:16:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:37306 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726921AbfAGQQX (ORCPT ); Mon, 7 Jan 2019 11:16:23 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 35EED2147C; Mon, 7 Jan 2019 16:16:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546877782; bh=uWjSlrvkw39gqwOG51hP7wzxnSNcL9yvELOQZCSvFZs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JA5AR9PS3uG0GrnKgt0mliHtv7Bkuf7BTuOu5IwqK9IRE9zuTOw9fwcHuzF1DCFON a4niN5ksbF2gipkWm6kmiQugzG8CFR650/hElEAJJjULk7gMHeRiU5IYSYiTJYXfGe sNGXKuBr48Dpsq4oU8/iTiLZGlg6+vp8wRV4AYuU= Date: Mon, 7 Jan 2019 17:16:20 +0100 From: Greg KH To: Kai-Heng Feng Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4] USB: Don't enable LPM if it's already enabled Message-ID: <20190107161620.GB2292@kroah.com> References: <20181203102643.22690-1-kai.heng.feng@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181203102643.22690-1-kai.heng.feng@canonical.com> User-Agent: Mutt/1.11.1 (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 03, 2018 at 06:26:43PM +0800, Kai-Heng Feng wrote: > USB Bluetooth controller QCA ROME (0cf3:e007) sometimes stops working > after S3: > [ 165.110742] Bluetooth: hci0: using NVM file: qca/nvm_usb_00000302.bin > [ 168.432065] Bluetooth: hci0: Failed to send body at 4 of 1953 (-110) > > After some experiments, I found that disabling LPM can workaround the > issue. > > On some platforms, the USB power is cut during S3, so the driver uses > reset-resume to resume the device. During port resume, LPM gets enabled > twice, by usb_reset_and_verify_device() and usb_port_resume(). > > So let's enable LPM for just once, as this solves the issue for the > device in question. > > Also consolidate USB2 LPM functions to usb_enable_usb2_hardware_lpm() > and usb_disable_usb2_hardware_lpm(). > > Signed-off-by: Kai-Heng Feng What kernel patch does this one "fix"? Adding a "Fixes:" tag would be good to try to figure out how far back in the kernel releases this should be backported. thanks, greg k-h