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,URIBL_BLOCKED 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 C55DCC43387 for ; Thu, 17 Jan 2019 10:25:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9173320851 for ; Thu, 17 Jan 2019 10:25:24 +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="NJ7PYJST"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="NJ7PYJST" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727418AbfAQKZT (ORCPT ); Thu, 17 Jan 2019 05:25:19 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:33708 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726966AbfAQKZT (ORCPT ); Thu, 17 Jan 2019 05:25:19 -0500 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id DDE5260388; Thu, 17 Jan 2019 10:25:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1547720717; bh=qZO8Vw1n57Ms4HPecyITg3sQ4OOYVquA9/mV22uu4y4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=NJ7PYJSTOUWmQs44xcgwtK2irtMkfwP5EqNYjUrSQbavwLgtNxKiZaSXEC/+EY0Nb g3p+mLpMFdhaxMQdnFIhJ99iD00thvRYR5D6BiQ6L331UK/gO5FgfDu/O7AUbXpltz nMaxJ27fhBx/Rx4mcHEIN2RbdwVyUCH+zSxd8yhk= Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 58CE560300; Thu, 17 Jan 2019 10:25:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1547720717; bh=qZO8Vw1n57Ms4HPecyITg3sQ4OOYVquA9/mV22uu4y4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=NJ7PYJSTOUWmQs44xcgwtK2irtMkfwP5EqNYjUrSQbavwLgtNxKiZaSXEC/+EY0Nb g3p+mLpMFdhaxMQdnFIhJ99iD00thvRYR5D6BiQ6L331UK/gO5FgfDu/O7AUbXpltz nMaxJ27fhBx/Rx4mcHEIN2RbdwVyUCH+zSxd8yhk= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 17 Jan 2019 15:55:17 +0530 From: Balakrishna Godavarthi To: Matthias Kaehlcke Cc: marcel@holtmann.org, johan.hedberg@gmail.com, linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH v8 1/3] Bluetooth: hci_qca: use wait_until_sent() for power pulses In-Reply-To: <20190116202253.GS261387@google.com> References: <20190116114603.500-1-bgodavar@codeaurora.org> <20190116114603.500-2-bgodavar@codeaurora.org> <20190116202253.GS261387@google.com> Message-ID: <482d8987d38f60dae1844bc30050cd06@codeaurora.org> 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 Matthias, On 2019-01-17 01:52, Matthias Kaehlcke wrote: > On Wed, Jan 16, 2019 at 05:16:01PM +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 >> --- >> Changes in v8: >> * Updated 1 second timeout instead of indefinite wait. >> >> Changes in v7: >> * updated the wait time to 5 ms after sending power pulses. >> >> Changes in v6: >> * added serdev_device_write_flush() in qca_send_power_pulse >> instead during the power off pulse. >> >> Changes in v5: >> * added serdev_device_write_flush() in qca_power_off(). >> --- >> drivers/bluetooth/hci_qca.c | 46 >> ++++++++++++++++--------------------- >> 1 file changed, 20 insertions(+), 26 deletions(-) >> >> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c >> index f036c8f98ea3..681bfa30467e 100644 >> --- a/drivers/bluetooth/hci_qca.c >> +++ b/drivers/bluetooth/hci_qca.c >> @@ -60,6 +60,7 @@ >> #define IBS_WAKE_RETRANS_TIMEOUT_MS 100 >> #define IBS_TX_IDLE_TIMEOUT_MS 2000 >> #define BAUDRATE_SETTLE_TIMEOUT_MS 300 >> +#define POWER_PULSE_TRANS_TIMEOUT_MS 1000 > > nit: Not that it should make a different in normal operation, but 1s > seems extreme. Is there really any chance that the byte hasn't been > sent after say 100ms (which is still an eternity for a single byte)? > >> /* susclk rate */ >> #define SUSCLK_RATE_32KHZ 32768 >> @@ -1013,11 +1014,10 @@ 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; >> + int timeout = __msecs_to_jiffies(POWER_PULSE_TRANS_TIMEOUT_MS); > > use msecs_to_jiffies() > [Bala]: will upadte. >> /* These power pulses are single byte command which are sent >> * at required baudrate to wcn3990. On wcn3990, we have an external >> @@ -1029,22 +1029,22 @@ 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 controller", cmd); >> >> + serdev_device_write_flush(hu->serdev); >> hci_uart_set_flow_control(hu, true); >> + ret = serdev_device_write_buf(hu->serdev, &cmd, sizeof(cmd)); >> + if (ret < 0) { >> + bt_dev_err(hu->hdev, "failed to send power pulse %02x", cmd); >> + return ret; >> + } >> >> - skb_put_u8(skb, cmd); >> - hci_skb_pkt_type(skb) = HCI_COMMAND_PKT; >> - >> - skb_queue_tail(&qca->txq, skb); >> - hci_uart_tx_wakeup(hu); >> - >> - /* Wait for 100 uS for SoC to settle down */ >> - usleep_range(100, 200); >> + serdev_device_wait_until_sent(hu->serdev, timeout); >> + /* Wait of 5ms is required for assuring to send the byte on the Tx >> + * line and also for the controller to settle down for the received >> + * byte. >> + */ >> + usleep_range(5000, 6000); > > I incorrectly claimed that there might be still bytes sitting in the > UART FIFO when serdev_device_wait_until_sent() returns, Johan > corrected me on that (thanks!). So if it takes the SoC 100us to settle > down we should be good with the original code. [Bala]: sure will revert, i think he commented that wait_until_sent() will only guarantee circular buffer is empty. if wait_until_sent() guarantee us that the data was transmitted from the FIFO, then 100us will work. > > Cheers > > Matthias -- Regards Balakrishna.