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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_SANE_1 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 6D2B0C43331 for ; Mon, 11 Nov 2019 09:27:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C22E20674 for ; Mon, 11 Nov 2019 09:27:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726832AbfKKJ1N (ORCPT ); Mon, 11 Nov 2019 04:27:13 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:60494 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726811AbfKKJ1N (ORCPT ); Mon, 11 Nov 2019 04:27:13 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: eballetbo) with ESMTPSA id 5EC8E283C86 Subject: Re: [PATCH v4 04/17] platform: chrome: cros-ec: record event timestamp in the hard irq To: Jonathan Cameron , Gwendal Grignou Cc: briannorris@chromium.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, lee.jones@linaro.org, bleung@chromium.org, dianders@chromium.org, groeck@chromium.org, fabien.lahoudere@collabora.com, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org References: <20191105222652.70226-1-gwendal@chromium.org> <20191105222652.70226-5-gwendal@chromium.org> <20191110121608.330bc0f7@archlinux> From: Enric Balletbo i Serra Message-ID: Date: Mon, 11 Nov 2019 10:27:07 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191110121608.330bc0f7@archlinux> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On 10/11/19 13:16, Jonathan Cameron wrote: > On Tue, 5 Nov 2019 14:26:39 -0800 > Gwendal Grignou wrote: > >> To improve sensor timestamp precision, given EC and AP are in >> different time domains, the AP needs to try to record the exact >> moment an event was signalled to the AP by the EC as soon as >> possible after it happens. >> >> First thing in the hard irq is the best place for this. >> >> Signed-off-by: Gwendal Grignou > A minor issue with kernel-doc (I think...) > > Otherwise, > Acked-by: Jonathan Cameron With the Jonathan's comment solved. Acked-by: Enric Balletbo i Serra Thanks, Enric >> --- >> Changes in v4: >> Check patch with --strict option >> Alignement >> No changes in v3. >> Changes in v2: >> Make cros_ec_get_time_ns inline. >> Using ktime_t instead of s64 when dealing with time. >> Added code in ishtp to gather timestamp. >> >> drivers/platform/chrome/cros_ec.c | 17 ++++++++++++++--- >> drivers/platform/chrome/cros_ec_ishtp.c | 17 +++++++++++++++-- >> drivers/platform/chrome/cros_ec_lpc.c | 2 ++ >> include/linux/platform_data/cros_ec_proto.h | 16 ++++++++++++++++ >> 4 files changed, 47 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c >> index 9b2d07422e17..925f84dbf621 100644 >> --- a/drivers/platform/chrome/cros_ec.c >> +++ b/drivers/platform/chrome/cros_ec.c >> @@ -31,6 +31,15 @@ static struct cros_ec_platform pd_p = { >> .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX), >> }; >> >> +static irqreturn_t ec_irq_handler(int irq, void *data) >> +{ >> + struct cros_ec_device *ec_dev = data; >> + >> + ec_dev->last_event_time = cros_ec_get_time_ns(); >> + >> + return IRQ_WAKE_THREAD; >> +} >> + >> static irqreturn_t ec_irq_thread(int irq, void *data) >> { >> struct cros_ec_device *ec_dev = data; >> @@ -141,9 +150,11 @@ int cros_ec_register(struct cros_ec_device *ec_dev) >> } >> >> if (ec_dev->irq) { >> - err = devm_request_threaded_irq(dev, ec_dev->irq, NULL, >> - ec_irq_thread, IRQF_TRIGGER_LOW | IRQF_ONESHOT, >> - "chromeos-ec", ec_dev); >> + err = devm_request_threaded_irq(dev, ec_dev->irq, >> + ec_irq_handler, >> + ec_irq_thread, >> + IRQF_TRIGGER_LOW | IRQF_ONESHOT, >> + "chromeos-ec", ec_dev); >> if (err) { >> dev_err(dev, "Failed to request IRQ %d: %d", >> ec_dev->irq, err); >> diff --git a/drivers/platform/chrome/cros_ec_ishtp.c b/drivers/platform/chrome/cros_ec_ishtp.c >> index 25ca2c894b4d..5c848f22b44b 100644 >> --- a/drivers/platform/chrome/cros_ec_ishtp.c >> +++ b/drivers/platform/chrome/cros_ec_ishtp.c >> @@ -200,13 +200,14 @@ static int ish_send(struct ishtp_cl_data *client_data, >> * process_recv() - Received and parse incoming packet >> * @cros_ish_cl: Client instance to get stats >> * @rb_in_proc: Host interface message buffer >> + * @timestamp: Timestamp of when parent callback started >> * >> * Parse the incoming packet. If it is a response packet then it will >> * update per instance flags and wake up the caller waiting to for the >> * response. If it is an event packet then it will schedule event work. >> */ >> static void process_recv(struct ishtp_cl *cros_ish_cl, >> - struct ishtp_cl_rb *rb_in_proc) >> + struct ishtp_cl_rb *rb_in_proc, ktime_t timestamp) >> { >> size_t data_len = rb_in_proc->buf_idx; >> struct ishtp_cl_data *client_data = >> @@ -295,6 +296,11 @@ static void process_recv(struct ishtp_cl *cros_ish_cl, >> break; >> >> case CROS_MKBP_EVENT: >> + /* >> + * Set timestamp from beginning of function since we actually >> + * got an incoming MKBP event >> + */ >> + client_data->ec_dev->last_event_time = timestamp; >> /* The event system doesn't send any data in buffer */ >> schedule_work(&client_data->work_ec_evt); >> >> @@ -322,10 +328,17 @@ static void ish_event_cb(struct ishtp_cl_device *cl_device) >> { >> struct ishtp_cl_rb *rb_in_proc; >> struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device); >> + ktime_t timestamp; >> + >> + /* >> + * Take timestamp as close to hardware interrupt as possible for sensor >> + * timestamps. >> + */ >> + timestamp = cros_ec_get_time_ns(); >> >> while ((rb_in_proc = ishtp_cl_rx_get_rb(cros_ish_cl)) != NULL) { >> /* Decide what to do with received data */ >> - process_recv(cros_ish_cl, rb_in_proc); >> + process_recv(cros_ish_cl, rb_in_proc, timestamp); >> } >> } >> >> diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c >> index 7d10d909435f..3c77496e164d 100644 >> --- a/drivers/platform/chrome/cros_ec_lpc.c >> +++ b/drivers/platform/chrome/cros_ec_lpc.c >> @@ -313,6 +313,8 @@ static void cros_ec_lpc_acpi_notify(acpi_handle device, u32 value, void *data) >> { >> struct cros_ec_device *ec_dev = data; >> >> + ec_dev->last_event_time = cros_ec_get_time_ns(); >> + >> if (ec_dev->mkbp_event_supported && >> cros_ec_get_next_event(ec_dev, NULL) > 0) >> blocking_notifier_call_chain(&ec_dev->event_notifier, 0, >> diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h >> index 691f9e953a96..b183024fef1f 100644 >> --- a/include/linux/platform_data/cros_ec_proto.h >> +++ b/include/linux/platform_data/cros_ec_proto.h >> @@ -122,6 +122,8 @@ struct cros_ec_command { >> * @event_data: Raw payload transferred with the MKBP event. >> * @event_size: Size in bytes of the event data. >> * @host_event_wake_mask: Mask of host events that cause wake from suspend. >> + * @last_event_time: exact time from the hard irq when we got notified of >> + * a new event. >> * @ec: The platform_device used by the mfd driver to interface with the >> * main EC. >> * @pd: The platform_device used by the mfd driver to interface with the >> @@ -162,6 +164,7 @@ struct cros_ec_device { >> int event_size; >> u32 host_event_wake_mask; >> u32 last_resume_result; >> + ktime_t last_event_time; >> >> /* The platform devices used by the mfd driver */ >> struct platform_device *ec; >> @@ -210,4 +213,17 @@ int cros_ec_check_features(struct cros_ec_dev *ec, int feature); >> >> int cros_ec_get_sensor_count(struct cros_ec_dev *ec); >> >> +/** >> + * cros_ec_get_time_ns - Return time in ns. > > Fairly sure that's not correct kernel-doc. Please run > ../scripts/kernel-doc over the files and fix the warnings. > > * cros_ec_get_time_ns() - Return time in ns. > >> + * >> + * This is the function used to record the time for last_event_time in struct >> + * cros_ec_device during the hard irq. >> + * >> + * Return: ktime_t format since boot. >> + */ >> +static inline ktime_t cros_ec_get_time_ns(void) >> +{ >> + return ktime_get_boottime_ns(); >> +} >> + >> #endif /* __LINUX_CROS_EC_PROTO_H */ >