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=-6.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS 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 C5FC5C43381 for ; Thu, 7 Mar 2019 06:52:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8EBB120675 for ; Thu, 7 Mar 2019 06:52:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="JqLlM7eQ"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="LSxHpZI5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726540AbfCGGwv (ORCPT ); Thu, 7 Mar 2019 01:52:51 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:38112 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726057AbfCGGwu (ORCPT ); Thu, 7 Mar 2019 01:52:50 -0500 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 5763E60316; Thu, 7 Mar 2019 06:52:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1551941570; bh=xMsAy5jX7PfN1+hij6szv5EyTekRG3WhVJp4UcLaYxg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=JqLlM7eQBQ0so2KQ+LAG15KVE8p1TEoO3T3EVVOrJe1BbLKUc9t7yh5Z3gWgPXUJf SJAG0kaLvNb6OlN29XwK+NZWhKpePcscX7OJYQoy96VUE8IxCrrk2MpNwce6IxcmhZ C0PGvwhUFQAdqSChtD8RiFDgovY1yO0E6cxdwkuQ= Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 98BBE60316; Thu, 7 Mar 2019 06:52:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1551941569; bh=xMsAy5jX7PfN1+hij6szv5EyTekRG3WhVJp4UcLaYxg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=LSxHpZI5KA1Ozls2zyFRGI0hSM2JyZF/bY6cre9UQ7WVWBnlypSe1k1Sar2FhvBCR Hpm0anw5TQuGbLDMP5ZA/u1wdkTk/iFbDBgIz2SoUy10F8cibxyz41KSezsW3ZYeSf zjcEM88HJrHbga80CEk+jJrYs0NWdNsirmT0XG1g= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Thu, 07 Mar 2019 14:52:49 +0800 From: rjliao@codeaurora.org To: Balakrishna Godavarthi Cc: Stephen Boyd , johan.hedberg@gmail.com, marcel@holtmann.org, mka@chromium.org, linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH v1] Bluetooth: hci_qca: Give enough time to ROME controller to bootup. In-Reply-To: References: <20190306162113.8585-1-bgodavar@codeaurora.org> <155191158734.20095.15990837191526416248@swboyd.mtv.corp.google.com> Message-ID: <9df1c9cbbe655d4aca9464cf7ca69900@codeaurora.org> X-Sender: rjliao@codeaurora.org User-Agent: Roundcube Webmail/1.2.5 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2019-03-07 14:49，Balakrishna Godavarthi 写道： > Hi Stepen, > > On 2019-03-07 04:03, Stephen Boyd wrote: >> Quoting Balakrishna Godavarthi (2019-03-06 08:21:13) >>> This patch enables enough time to ROME controller to bootup >>> after we bring the enable ping out of reset. >>> >>> Signed-off-by: Balakrishna Godavarthi >>> --- >> >> Any Fixes tag? And maybe some more explanation or background on where >> 150 ms sleep comes from would be useful. Was it determined >> experimentally or did it come from a datasheet somewhere? Does the >> time >> differ between boards? >> > [Bala]: this was observed in our stress testing and even the CHIP > firmware team > confirmed that BT chip required at least 150 ms to boot up. > > @Rocky to confirm my statement. > >>> drivers/bluetooth/hci_qca.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/drivers/bluetooth/hci_qca.c >>> b/drivers/bluetooth/hci_qca.c >>> index 237aea34b69f..1953b13511e7 100644 >>> --- a/drivers/bluetooth/hci_qca.c >>> +++ b/drivers/bluetooth/hci_qca.c >>> @@ -508,6 +508,8 @@ static int qca_open(struct hci_uart *hu) >>> qcadev = serdev_device_get_drvdata(hu->serdev); >>> if (qcadev->btsoc_type != QCA_WCN3990) { >>> gpiod_set_value_cansleep(qcadev->bt_en, 1); >>> + /* Controller needs time to bootup. */ >>> + msleep(150); >>> } else { >>> hu->init_speed = qcadev->init_speed; >>> hu->oper_speed = qcadev->oper_speed; Yes,ROME firmware needs 150ms to boot up after toggle the BT_EN pin.