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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 36428CA9EA0 for ; Fri, 18 Oct 2019 18:03:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 01708222C5 for ; Fri, 18 Oct 2019 18:03:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="daWXD1ny" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2505648AbfJRSDm (ORCPT ); Fri, 18 Oct 2019 14:03:42 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:33382 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2505622AbfJRSDm (ORCPT ); Fri, 18 Oct 2019 14:03:42 -0400 Received: by mail-pg1-f195.google.com with SMTP id i76so3798132pgc.0 for ; Fri, 18 Oct 2019 11:03:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=8/ZS+906/9FcfZAV3qaij45dj3UK3E6lm1Y4pz31ip8=; b=daWXD1nygLkP7A5y9K7cowvo3WWYzDRQR4UTxSWALIoMmSexkvrCrGbeludebonnvR lSrvphIFIfHSlvohBF/QW0GdN/0BsjuoIvIcxsQuANTT4o9vsQRiUUtH812PSNUysuQE qTp+cenvmSFjrNCkI12Nt/5rIi7qyfyNrhRto= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=8/ZS+906/9FcfZAV3qaij45dj3UK3E6lm1Y4pz31ip8=; b=JULLp00QPya8i8AkHkZ5U+Uam8mmBR2UmKgSCRU5paqLqIBDeWuhppmW2VTFHy8oye q9fXYhgbFoPc0lNZLSm/XgsMWjjeuuP+vxU0ndAdoJZOLhjgoFipzWfW1pCvde73D2Rq P8Dl5xO3qu78zMTxuSSxIYzHlHxQUKgvwHWzB+/EA/VBuynID5kVQ/AaKsFgu7pRr1k8 Ta3W0J5kzGAmHeOfuWVkpimas8KBT3nk2wCL4IRICVnjOpzktPPQDguZ5y5M+yZ8Bpgp N7gaf7fkcqBDBgAMYc4YLxV1M83+SAI9PSSoILPZozSK9B8HQLB35akWncGhL+XAELMO 75rw== X-Gm-Message-State: APjAAAXenepHQDOev0dyeAq+micglRUlJN9QUQNrF7xB8v10u2Bf2xi3 bmi0R4c3RtwK/8UygRoz6ax4Mw== X-Google-Smtp-Source: APXvYqzPFGfktG3Py1x/vmEI6cC7z8QO39KHafDjtPfHiiUUnrPmfUmcK6PTAQJBIhon1QiV/qEFuA== X-Received: by 2002:a63:c901:: with SMTP id o1mr11394460pgg.66.1571421821320; Fri, 18 Oct 2019 11:03:41 -0700 (PDT) Received: from localhost ([2620:15c:202:1:4fff:7a6b:a335:8fde]) by smtp.gmail.com with ESMTPSA id y66sm7424489pgy.23.2019.10.18.11.03.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 18 Oct 2019 11:03:40 -0700 (PDT) Date: Fri, 18 Oct 2019 11:03:39 -0700 From: Matthias Kaehlcke To: Jeffrey Hugo Cc: marcel@holtmann.org, johan.hedberg@gmail.com, c-hbandi@codeaurora.org, bgodavar@codeaurora.org, linux-bluetooth@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Bluetooth: hci_qca: Add delay for wcn3990 stability Message-ID: <20191018180339.GQ87296@google.com> References: <20191017212955.6266-1-jeffrey.l.hugo@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20191017212955.6266-1-jeffrey.l.hugo@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Thu, Oct 17, 2019 at 02:29:55PM -0700, Jeffrey Hugo wrote: > On the msm8998 mtp, the response to the baudrate change command is never > received. On the Lenovo Miix 630, the response to the baudrate change > command is corrupted - "Frame reassembly failed (-84)". > > Adding a 50ms delay before re-enabling flow to receive the baudrate change > command response from the wcn3990 addesses both issues, and allows > bluetooth to become functional. >From my earlier debugging on sdm845 I don't think this is what happens. The problem is that the wcn3990 sends the response to the baudrate change command using the new baudrate, while the UART on the SoC still operates with the prior speed (for details see 2faa3f15fa2f ("Bluetooth: hci_qca: wcn3990: Drop baudrate change vendor event")) IIRC the 50ms delay causes the HCI core to discard the received data, which is why the "Frame reassembly failed" message disappears, not because the response was received. In theory commit 78e8fa2972e5 ("Bluetooth: hci_qca: Deassert RTS while baudrate change command") should have fixed those messages, do you know if CTS/RTS are connected on the Bluetooth UART of the Lenovo Miix 630?