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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,URIBL_RHS_DOB autolearn=unavailable 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 A2530C04EB9 for ; Thu, 6 Dec 2018 10:40:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5FBAB20989 for ; Thu, 6 Dec 2018 10:40:15 +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="brQgcnZr"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="V7i27NWm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5FBAB20989 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-bluetooth-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728482AbeLFKkJ (ORCPT ); Thu, 6 Dec 2018 05:40:09 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:58134 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727575AbeLFKkJ (ORCPT ); Thu, 6 Dec 2018 05:40:09 -0500 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 716ED607B5; Thu, 6 Dec 2018 10:40:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1544092808; bh=fUivZL1s5upLZ6o4BY6b7ICJk+NquYmE+NS6SkUqvb0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=brQgcnZrc39UBOq3uo71BZ6Em/BpdDcNbzGA6x9z5dtn6zSZSYfHhOyCwtGPxoNLz G/xb9qSuudDUSS+0TvGoKjx+wi8F171+/qL2u32dhfFB4QiR1AEM8WVkKmakqw5sQX rn8Vo2XXcYJqyEm6W/6XMJLkDCTer5a/236GEKj4= Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id E071460792; Thu, 6 Dec 2018 10:40:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1544092807; bh=fUivZL1s5upLZ6o4BY6b7ICJk+NquYmE+NS6SkUqvb0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=V7i27NWmde+SYh9gGSpWeqnVq3H4/HRcwjSy4AraCRD9fKuz5nQBLvrnJzHx1JMN0 b88B+LGnCyM7SBD/ET/D9QBWP3Q0NibBKLvFaYC41D9LeczkXYcK+H7dqH1WukB7t9 cdO7bKoRJxst3ldCmXpDVCdWSQ4N3oL63MxwRbCk= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 06 Dec 2018 16:10:07 +0530 From: Balakrishna Godavarthi To: Johan Hovold Cc: marcel@holtmann.org, johan.hedberg@gmail.com, mka@chromium.org, linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org, Johan Hovold Subject: Re: [PATCH v3 1/4] Bluetooth: hci_qca: use wait_until_sent() for power pulses In-Reply-To: <20181205062503.GG18087@localhost> References: <20181130150247.26294-1-bgodavar@codeaurora.org> <20181130150247.26294-2-bgodavar@codeaurora.org> <20181205062503.GG18087@localhost> Message-ID: X-Sender: bgodavar@codeaurora.org User-Agent: Roundcube Webmail/1.2.5 Sender: linux-bluetooth-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org Hi Johan, On 2018-12-05 11:55, Johan Hovold wrote: > On Fri, Nov 30, 2018 at 08:32:44PM +0530, Balakrishna Godavarthi wrote: >> wcn3990 requires a power pulse to turn ON/OFF along with >> regulators. Sometimes we are observing the power pulses are sent >> out with some time delay, due to queuing these commands. This is >> causing synchronization issues with chip, which intern delay the >> chip setup or may end up with communication issues. >> >> Signed-off-by: Balakrishna Godavarthi >> --- >> v3: >> * no change. >> v2: >> * Updated function qca_send_power_pulse() >> * addressed reviewer comments. > > Please make sure to include reviewers on CC when resending, and as > someone else already mentioned, be a bit more specific about what > changes you actually made in response to the review feedback you > received. > [Bala]: sure will add and provide more info in version change history. >> v1: >> * initial patch >> --- >> drivers/bluetooth/hci_qca.c | 37 >> +++++++++++++------------------------ >> 1 file changed, 13 insertions(+), 24 deletions(-) >> >> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c >> index f036c8f98ea3..f5dd323c1967 100644 >> --- a/drivers/bluetooth/hci_qca.c >> +++ b/drivers/bluetooth/hci_qca.c >> @@ -1013,11 +1013,9 @@ static inline void host_set_baudrate(struct >> hci_uart *hu, unsigned int speed) >> hci_uart_set_baudrate(hu, speed); >> } >> >> -static int qca_send_power_pulse(struct hci_dev *hdev, u8 cmd) >> +static int qca_send_power_pulse(struct hci_uart *hu, u8 cmd) >> { >> - struct hci_uart *hu = hci_get_drvdata(hdev); >> - struct qca_data *qca = hu->priv; >> - struct sk_buff *skb; >> + int ret; >> >> /* These power pulses are single byte command which are sent >> * at required baudrate to wcn3990. On wcn3990, we have an external >> @@ -1029,19 +1027,16 @@ static int qca_send_power_pulse(struct hci_dev >> *hdev, u8 cmd) >> * save power. Disabling hardware flow control is mandatory while >> * sending power pulses to SoC. >> */ >> - bt_dev_dbg(hdev, "sending power pulse %02x to SoC", cmd); >> - >> - skb = bt_skb_alloc(sizeof(cmd), GFP_KERNEL); >> - if (!skb) >> - return -ENOMEM; >> - >> + bt_dev_dbg(hu->hdev, "sending power pulse %02x to SoC", cmd); >> hci_uart_set_flow_control(hu, true); >> + ret = serdev_device_write(hu->serdev, &cmd, sizeof(cmd), 0); > > You're still using 0 as a timeout here which is broken, as I already > told you. > [Bala]: got the change now will update to timeout to non zero value. > From 4.21 this will result in an indefinite timeout, but currently > implies not to wait for a full write buffer to drain at all. > > As I also mentioned, you need to to make sure to call > serdev_device_write_wakeup() in the write_wakup() path if you are going > to use serdev_device_write() at all. > [Bala]: this where i am confused. calling serdev_device_write is calling an wakeup internally. below is the flow ttyport_write_buf: * calling serdev_device_write() will call write_buf() in this call we are enabling bit "TTY_DO_WRITE_WAKEUP" and calling write() i.e. uart_write() where we call in start_tx. this will go to the vendor specific write where in isr we call uart_write_wakeup() https://elixir.bootlin.com/linux/latest/source/drivers/tty/serial/qcom_geni_serial.c#L756 uart_write_wakeup()->ttyport_write_wakeup()->serdev_controller_write_wakeup()->hci_uart_write_wakeup()->hci_uart_tx_wakeup() the above is flow when serdev_device_write() is called, it is indirectly calling serdev_write_wakeup(). Why actual we need to call an serdev_write_wakeup() is this wakeup related to the UART port or for the BT chip. > Johan -- Regards Balakrishna.