From patchwork Fri Sep 17 12:27:18 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Jonas_Dre=C3=9Fler?= X-Patchwork-Id: 12501821 X-Patchwork-Delegate: johannes@sipsolutions.net 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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 55F66C433F5 for ; Fri, 17 Sep 2021 12:27:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CA4C6008E for ; Fri, 17 Sep 2021 12:27:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243593AbhIQM3N (ORCPT ); Fri, 17 Sep 2021 08:29:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235941AbhIQM3M (ORCPT ); Fri, 17 Sep 2021 08:29:12 -0400 Received: from mout-p-102.mailbox.org (mout-p-102.mailbox.org [IPv6:2001:67c:2050::465:102]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AF39C061574; Fri, 17 Sep 2021 05:27:49 -0700 (PDT) Received: from smtp202.mailbox.org (smtp202.mailbox.org [IPv6:2001:67c:2050:105:465:1:4:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-102.mailbox.org (Postfix) with ESMTPS id 4H9tWd0rlbzQjgX; Fri, 17 Sep 2021 14:27:41 +0200 (CEST) X-Virus-Scanned: amavisd-new at heinlein-support.de From: =?utf-8?q?Jonas_Dre=C3=9Fler?= To: Amitkumar Karwar , Ganapathi Bhat , Xinming Hu , Kalle Valo , "David S. Miller" , Jakub Kicinski , Marcel Holtmann , Johan Hedberg , Luiz Augusto von Dentz Cc: =?utf-8?q?Jonas_Dre=C3=9Fler?= , Tsuchiya Yuto , linux-wireless@vger.kernel.org, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, Maximilian Luz , Andy Shevchenko , =?utf-8?q?Pali_Roh?= =?utf-8?q?=C3=A1r?= Subject: [PATCH] Bluetooth: btusb: Lower passive lescan interval on Marvell 88W8897 Date: Fri, 17 Sep 2021 14:27:18 +0200 Message-Id: <20210917122718.86776-1-verdre@v0yd.nl> MIME-Version: 1.0 X-Rspamd-Queue-Id: 9094037F Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org The Marvell 88W8897 combined wifi and bluetooth card (pcie+usb version) is used in a lot of Microsoft Surface devices, and all those devices suffer from very low 2.4GHz wifi connection speeds while bluetooth is enabled. The reason for that is that the default passive scanning interval for Bluetooth Low Energy devices is quite high on Linux (interval of 60 msec and scan window of 30 msec, see le_scan_interval and le_scan_window in hci_core.c), and the Marvell chip is known for its bad bt+wifi coexisting performance. So decrease that passive scan interval and make the scan window shorter on this particular device to allow for spending more time transmitting wifi signals: The new scan interval is 250 msec (0x190 * 0.625 msec) and the new scan window is 6.25 msec (0xa * 0.625 msec). This change has a very large impact on the 2.4GHz wifi speeds and gets it up to performance comparable with the Windows driver, which seems to apply a similar quirk. The scan interval and scan window length were tested and found to work very well with a bunch of Bluetooth Low Energy devices, including the Surface Pen, a Bluetooth Speaker and two modern Bluetooth headphones. All devices were discovered immediately after turning them on. Even lower values were also tested, but these introduced longer delays until devices get discovered. Signed-off-by: Jonas Dreßler --- drivers/bluetooth/btusb.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c index 60d2fce59a71..05b11179c839 100644 --- a/drivers/bluetooth/btusb.c +++ b/drivers/bluetooth/btusb.c @@ -59,6 +59,7 @@ static struct usb_driver btusb_driver; #define BTUSB_WIDEBAND_SPEECH 0x400000 #define BTUSB_VALID_LE_STATES 0x800000 #define BTUSB_QCA_WCN6855 0x1000000 +#define BTUSB_LOWER_LESCAN_INTERVAL 0x2000000 #define BTUSB_INTEL_BROKEN_INITIAL_NCMD 0x4000000 static const struct usb_device_id btusb_table[] = { @@ -356,6 +357,7 @@ static const struct usb_device_id blacklist_table[] = { { USB_DEVICE(0x1286, 0x2044), .driver_info = BTUSB_MARVELL }, { USB_DEVICE(0x1286, 0x2046), .driver_info = BTUSB_MARVELL }, { USB_DEVICE(0x1286, 0x204e), .driver_info = BTUSB_MARVELL }, + { USB_DEVICE(0x1286, 0x204c), .driver_info = BTUSB_LOWER_LESCAN_INTERVAL }, /* Intel Bluetooth devices */ { USB_DEVICE(0x8087, 0x0025), .driver_info = BTUSB_INTEL_COMBINED }, @@ -3813,6 +3815,19 @@ static int btusb_probe(struct usb_interface *intf, if (id->driver_info & BTUSB_MARVELL) hdev->set_bdaddr = btusb_set_bdaddr_marvell; + /* The Marvell 88W8897 combined wifi and bluetooth card is known for + * very bad bt+wifi coexisting performance. + * + * Decrease the passive BT Low Energy scan interval a bit + * (0x0190 * 0.625 msec = 250 msec) and make the scan window shorter + * (0x000a * 0,625 msec = 6.25 msec). This allows for significantly + * higher wifi throughput while passively scanning for BT LE devices. + */ + if (id->driver_info & BTUSB_LOWER_LESCAN_INTERVAL) { + hdev->le_scan_interval = 0x0190; + hdev->le_scan_window = 0x000a; + } + if (IS_ENABLED(CONFIG_BT_HCIBTUSB_MTK) && (id->driver_info & BTUSB_MEDIATEK)) { hdev->setup = btusb_mtk_setup;