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=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS 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 245A9CA9EB0 for ; Sun, 3 Nov 2019 17:27:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DCD2D20578 for ; Sun, 3 Nov 2019 17:27:35 +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="GeBoxngE"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="hha+JUFe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727890AbfKCR1b (ORCPT ); Sun, 3 Nov 2019 12:27:31 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:54650 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727444AbfKCR1b (ORCPT ); Sun, 3 Nov 2019 12:27:31 -0500 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 9FEFB6146C; Sun, 3 Nov 2019 17:27:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1572802050; bh=IFE+63smCDWoDt/0woRS2mcV78/GgXb+lPWFsBFdH3A=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=GeBoxngEk7NiAq1Tvxd8YWimm3G+78kWmp3NrNPXyp/8twgpR0knQ7jGp6wkyLebj hGs27kjenmU2r35MBFy85/FfFZn+R80pJnKYZI1BIwLRC9/8sKD8X2Phlhs5IaXGez cDTfYix/rri7GUvr3myWVKKo1mNce6dN2zm8x/rw= Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 2B51861327; Sun, 3 Nov 2019 17:27:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1572802049; bh=IFE+63smCDWoDt/0woRS2mcV78/GgXb+lPWFsBFdH3A=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=hha+JUFeOBcjuLIWOkReecH5D6sRgiVQjdazICbYcl1EeVTAn2PS/v7pgUxs5ifVA r/ABBdpU6lbmhbBdXDAI9bViHxPWmcRN4jB4EMjvS+4pG/wU9NRQUNMgbmivlB1QgX ywT3ewwZil65n20PGCPjQa8+FIePGWmyYstYtmDM= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Sun, 03 Nov 2019 22:57:29 +0530 From: Balakrishna Godavarthi To: Claire Chang Cc: Marcel Holtmann , Johan Hedberg , rjliao@codeaurora.org, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Bluetooth: hci_qca: add PM support In-Reply-To: <20191031104614.165120-1-tientzu@chromium.org> References: <20191031104614.165120-1-tientzu@chromium.org> Message-ID: X-Sender: bgodavar@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 On 2019-10-31 16:16, Claire Chang wrote: > Add PM suspend/resume callbacks for hci_qca driver. > > BT host will make sure both Rx and Tx go into sleep state in > qca_suspend. Without this, Tx may still remain in awake state, which > prevents BTSOC from entering deep sleep. For example, BlueZ will send > Set Event Mask to device when suspending and this will wake the device > Rx up. However, the Tx idle timeout on the host side is 2000 ms. If the > host is suspended before its Tx idle times out, it won't send > HCI_IBS_SLEEP_IND to the device and the device Rx will remain awake. > > We implement this by canceling relevant work in workqueue, sending > HCI_IBS_SLEEP_IND to the device and then waiting HCI_IBS_SLEEP_IND sent > by the device. > > In order to prevent the device from being awaken again after > qca_suspend > is called, we introduce QCA_SUSPEND flag. QCA_SUSPEND is set in the > beginning of qca_suspend to indicate system is suspending and that we'd > like to ignore any further wake events. > > With QCA_SUSPEND and spinlock, we can avoid race condition, e.g. if > qca_enqueue acquires qca->hci_ibs_lock before qca_suspend calls > cancel_work_sync and then qca_enqueue adds a new qca->ws_awake_device > work after the previous one is cancelled. > > If BTSOC wants to wake the whole system up after qca_suspend is called, > it will keep sending HCI_IBS_WAKE_IND and uart driver will take care of > waking the system. For example, uart driver will reconfigure its Rx pin > to a normal GPIO pin and enable irq wake on that pin when suspending. > Once host detects Rx falling, the system will begin resuming. Then, the > BT host clears QCA_SUSPEND flag in qca_resume and begins dealing with > normal HCI packets. By doing so, only a few HCI_IBS_WAKE_IND packets > are > lost and there is no data packet loss. > > Signed-off-by: Claire Chang > --- > drivers/bluetooth/hci_qca.c | 127 +++++++++++++++++++++++++++++++++++- > 1 file changed, 124 insertions(+), 3 deletions(-) > > diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c > index c591a8ba9d93..c2062087b46b 100644 > --- a/drivers/bluetooth/hci_qca.c > +++ b/drivers/bluetooth/hci_qca.c > @@ -43,7 +43,8 @@ > #define HCI_MAX_IBS_SIZE 10 > > #define IBS_WAKE_RETRANS_TIMEOUT_MS 100 > -#define IBS_TX_IDLE_TIMEOUT_MS 2000 > +#define IBS_BTSOC_TX_IDLE_TIMEOUT_MS 40 > +#define IBS_HOST_TX_IDLE_TIMEOUT_MS 2000 > #define CMD_TRANS_TIMEOUT_MS 100 > > /* susclk rate */ > @@ -55,6 +56,7 @@ > enum qca_flags { > QCA_IBS_ENABLED, > QCA_DROP_VENDOR_EVENT, > + QCA_SUSPENDING, > }; > > /* HCI_IBS transmit side sleep protocol states */ > @@ -100,6 +102,7 @@ struct qca_data { > struct work_struct ws_tx_vote_off; > unsigned long flags; > struct completion drop_ev_comp; > + wait_queue_head_t suspend_wait_q; > > /* For debugging purpose */ > u64 ibs_sent_wacks; > @@ -437,6 +440,12 @@ static void hci_ibs_wake_retrans_timeout(struct > timer_list *t) > spin_lock_irqsave_nested(&qca->hci_ibs_lock, > flags, SINGLE_DEPTH_NESTING); > > + /* Don't retransmit the HCI_IBS_WAKE_IND when suspending. */ > + if (test_bit(QCA_SUSPENDING, &qca->flags)) { > + spin_unlock_irqrestore(&qca->hci_ibs_lock, flags); > + return; > + } > + > switch (qca->tx_ibs_state) { > case HCI_IBS_TX_WAKING: > /* No WAKE_ACK, retransmit WAKE */ > @@ -496,6 +505,8 @@ static int qca_open(struct hci_uart *hu) > INIT_WORK(&qca->ws_rx_vote_off, qca_wq_serial_rx_clock_vote_off); > INIT_WORK(&qca->ws_tx_vote_off, qca_wq_serial_tx_clock_vote_off); > > + init_waitqueue_head(&qca->suspend_wait_q); > + > qca->hu = hu; > init_completion(&qca->drop_ev_comp); > > @@ -532,7 +543,7 @@ static int qca_open(struct hci_uart *hu) > qca->wake_retrans = IBS_WAKE_RETRANS_TIMEOUT_MS; > > timer_setup(&qca->tx_idle_timer, hci_ibs_tx_idle_timeout, 0); > - qca->tx_idle_delay = IBS_TX_IDLE_TIMEOUT_MS; > + qca->tx_idle_delay = IBS_HOST_TX_IDLE_TIMEOUT_MS; > > BT_DBG("HCI_UART_QCA open, tx_idle_delay=%u, wake_retrans=%u", > qca->tx_idle_delay, qca->wake_retrans); > @@ -647,6 +658,12 @@ static void device_want_to_wakeup(struct hci_uart > *hu) > > qca->ibs_recv_wakes++; > > + /* Don't wake the rx up when suspending. */ > + if (test_bit(QCA_SUSPENDING, &qca->flags)) { > + spin_unlock_irqrestore(&qca->hci_ibs_lock, flags); > + return; > + } > + > switch (qca->rx_ibs_state) { > case HCI_IBS_RX_ASLEEP: > /* Make sure clock is on - we may have turned clock off since > @@ -711,6 +728,8 @@ static void device_want_to_sleep(struct hci_uart > *hu) > break; > } > > + wake_up_interruptible(&qca->suspend_wait_q); > + > spin_unlock_irqrestore(&qca->hci_ibs_lock, flags); > } > > @@ -728,6 +747,12 @@ static void device_woke_up(struct hci_uart *hu) > > qca->ibs_recv_wacks++; > > + /* Don't react to the wake-up-acknowledgment when suspending. */ > + if (test_bit(QCA_SUSPENDING, &qca->flags)) { > + spin_unlock_irqrestore(&qca->hci_ibs_lock, flags); > + return; > + } > + > switch (qca->tx_ibs_state) { > case HCI_IBS_TX_AWAKE: > /* Expect one if we send 2 WAKEs */ > @@ -780,8 +805,10 @@ static int qca_enqueue(struct hci_uart *hu, > struct sk_buff *skb) > > /* Don't go to sleep in middle of patch download or > * Out-Of-Band(GPIOs control) sleep is selected. > + * Don't wake the device up when suspending. > */ > - if (!test_bit(QCA_IBS_ENABLED, &qca->flags)) { > + if (!test_bit(QCA_IBS_ENABLED, &qca->flags) || > + test_bit(QCA_SUSPENDING, &qca->flags)) { > skb_queue_tail(&qca->txq, skb); > spin_unlock_irqrestore(&qca->hci_ibs_lock, flags); > return 0; > @@ -1539,6 +1566,99 @@ static void qca_serdev_remove(struct > serdev_device *serdev) > hci_uart_unregister_device(&qcadev->serdev_hu); > } > > +static int __maybe_unused qca_suspend(struct device *dev) > +{ > + struct hci_dev *hdev = container_of(dev, struct hci_dev, dev); > + struct hci_uart *hu = hci_get_drvdata(hdev); > + struct qca_data *qca = hu->priv; > + unsigned long flags; > + int ret = 0; > + u8 cmd; > + > + set_bit(QCA_SUSPENDING, &qca->flags); > + > + /* Device is downloading patch or doesn't support in-band sleep. */ > + if (!test_bit(QCA_IBS_ENABLED, &qca->flags)) > + return 0; > + > + cancel_work_sync(&qca->ws_awake_device); > + cancel_work_sync(&qca->ws_awake_rx); > + > + spin_lock_irqsave_nested(&qca->hci_ibs_lock, > + flags, SINGLE_DEPTH_NESTING); > + > + switch (qca->tx_ibs_state) { > + case HCI_IBS_TX_WAKING: > + del_timer(&qca->wake_retrans_timer); > + /* Fall through */ > + case HCI_IBS_TX_AWAKE: > + del_timer(&qca->tx_idle_timer); > + > + serdev_device_write_flush(hu->serdev); > + cmd = HCI_IBS_SLEEP_IND; > + ret = serdev_device_write_buf(hu->serdev, &cmd, sizeof(cmd)); > + > + if (ret < 0) { > + BT_ERR("Failed to send SLEEP to device"); > + break; > + } > + > + qca->tx_ibs_state = HCI_IBS_TX_ASLEEP; > + qca->ibs_sent_slps++; > + > + qca_wq_serial_tx_clock_vote_off(&qca->ws_tx_vote_off); > + break; > + > + case HCI_IBS_TX_ASLEEP: > + break; > + > + default: > + BT_ERR("Spurious tx state %d", qca->tx_ibs_state); > + ret = -EINVAL; > + break; > + } > + > + spin_unlock_irqrestore(&qca->hci_ibs_lock, flags); > + > + if (ret < 0) > + goto error; > + > + serdev_device_wait_until_sent(hu->serdev, > + msecs_to_jiffies(CMD_TRANS_TIMEOUT_MS)); > + > + /* Wait for HCI_IBS_SLEEP_IND sent by device to indicate its Tx is > going > + * to sleep, so that the packet does not wake the system later. > + */ > + > + ret = wait_event_interruptible_timeout(qca->suspend_wait_q, > + qca->rx_ibs_state == HCI_IBS_RX_ASLEEP, > + msecs_to_jiffies(IBS_BTSOC_TX_IDLE_TIMEOUT_MS)); > + > + if (ret > 0) > + return 0; > + > + if (ret == 0) > + ret = -ETIMEDOUT; > + > +error: > + clear_bit(QCA_SUSPENDING, &qca->flags); > + > + return ret; > +} > + > +static int __maybe_unused qca_resume(struct device *dev) > +{ > + struct hci_dev *hdev = container_of(dev, struct hci_dev, dev); > + struct hci_uart *hu = hci_get_drvdata(hdev); > + struct qca_data *qca = hu->priv; > + > + clear_bit(QCA_SUSPENDING, &qca->flags); > + > + return 0; > +} > + > +static SIMPLE_DEV_PM_OPS(qca_pm_ops, qca_suspend, qca_resume); > + > static const struct of_device_id qca_bluetooth_of_match[] = { > { .compatible = "qcom,qca6174-bt" }, > { .compatible = "qcom,wcn3990-bt", .data = &qca_soc_data_wcn3990}, > @@ -1553,6 +1673,7 @@ static struct serdev_device_driver > qca_serdev_driver = { > .driver = { > .name = "hci_uart_qca", > .of_match_table = qca_bluetooth_of_match, > + .pm = &qca_pm_ops, > }, > }; Reviewed-by: Balakrishna Godavarthi -- Regards Balakrishna.