From patchwork Tue Oct 30 05:54:52 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kai-Heng Feng X-Patchwork-Id: 10660473 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DC8801751 for ; Tue, 30 Oct 2018 05:55:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CAF4229E8D for ; Tue, 30 Oct 2018 05:55:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BD3C129E95; Tue, 30 Oct 2018 05:55:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3BF5229E8D for ; Tue, 30 Oct 2018 05:55:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726105AbeJ3OrC (ORCPT ); Tue, 30 Oct 2018 10:47:02 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:43899 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726050AbeJ3OrC (ORCPT ); Tue, 30 Oct 2018 10:47:02 -0400 Received: from 61-220-137-37.hinet-ip.hinet.net ([61.220.137.37] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1gHMzQ-00031a-QQ; Tue, 30 Oct 2018 05:54:57 +0000 From: Kai-Heng Feng To: gregkh@linuxfoundation.org Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Kai-Heng Feng Subject: [PATCH] USB: Don't enable LPM if it's already enabled Date: Tue, 30 Oct 2018 13:54:52 +0800 Message-Id: <20181030055452.25969-1-kai.heng.feng@canonical.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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. Signed-off-by: Kai-Heng Feng --- drivers/usb/core/driver.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 53564386ed57..e11d2eac76b6 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -1901,7 +1901,8 @@ int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable) struct usb_hcd *hcd = bus_to_hcd(udev->bus); int ret = -EPERM; - if (enable && !udev->usb2_hw_lpm_allowed) + if (enable && !udev->usb2_hw_lpm_allowed || + udev->usb2_hw_lpm_enabled == enable) return 0; if (hcd->driver->set_usb2_hw_lpm) {