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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 559CCC17443 for ; Sun, 10 Nov 2019 12:31:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 228A320B7C for ; Sun, 10 Nov 2019 12:31:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573389066; bh=08tTd3Kp1eVd05tgOQ/l7s/1n4h1NTJgwCA1oHYjeZs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=rNWyo+ihzb9UBoBoYla3rOkPDlxgSfU78Umlvzhz5R9B2GAnbbu4p0hBXv7wUPLng eglrdaO3tT4wAoeoc7VEE8vQVVN2QfCt6ovif4kHWON7/H7IfJsA1SNG3XHTEYhRM+ cvYDM9kt7rq8ozt59YP2Vm7wJ4HV9bjVgJKl1quM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726793AbfKJMbF (ORCPT ); Sun, 10 Nov 2019 07:31:05 -0500 Received: from mail.kernel.org ([198.145.29.99]:54400 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726741AbfKJMbE (ORCPT ); Sun, 10 Nov 2019 07:31:04 -0500 Received: from archlinux (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1A45120869; Sun, 10 Nov 2019 12:31:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573389063; bh=08tTd3Kp1eVd05tgOQ/l7s/1n4h1NTJgwCA1oHYjeZs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=anKE2sMosm4Uo43FIC24gMt2PkSkMZbR1eh199OYGplP0iRZNLn3Sf4SGHMTUlaq/ rjSBEo0RKqDbfWnL7lxYzLFmHi6jMPpIfq5plXK5uFEfFw9RTP5OSOWIMUF3GzT6wF 34/ajQVjp9l3ogfl122D9saH42riq2ZXvWzAASK4= Date: Sun, 10 Nov 2019 12:16:08 +0000 From: Jonathan Cameron To: Gwendal Grignou Cc: briannorris@chromium.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, lee.jones@linaro.org, bleung@chromium.org, enric.balletbo@collabora.com, dianders@chromium.org, groeck@chromium.org, fabien.lahoudere@collabora.com, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org Subject: Re: [PATCH v4 04/17] platform: chrome: cros-ec: record event timestamp in the hard irq Message-ID: <20191110121608.330bc0f7@archlinux> In-Reply-To: <20191105222652.70226-5-gwendal@chromium.org> References: <20191105222652.70226-1-gwendal@chromium.org> <20191105222652.70226-5-gwendal@chromium.org> X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > --- > 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 */