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,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 4B50EC47404 for ; Sat, 5 Oct 2019 16:16:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1FC55222CA for ; Sat, 5 Oct 2019 16:16:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570292203; bh=zFFS8k2lbRbcQL+fckDvfr83fOZaAsE77ehiJSvGoLI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=uDqs8cHKrrbavi2HXtOf1/HcGoV49GAEnXWD8vA24LLNcAl7WZvvyMtHuedJQagNy aPupRluqB4BtNcKgywSVU8pyis1cOY8YPmJfGV0A2pbS2hwZyI9v9SAoMks7kL4Qyz rzksfF84wQXtCSYbLqqFA6hJkvttjI5HVe7/4Mj8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729238AbfJEQQm (ORCPT ); Sat, 5 Oct 2019 12:16:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:39188 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728101AbfJEQQm (ORCPT ); Sat, 5 Oct 2019 12:16:42 -0400 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 8D2CA222C8; Sat, 5 Oct 2019 16:16:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570292200; bh=zFFS8k2lbRbcQL+fckDvfr83fOZaAsE77ehiJSvGoLI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=sFVmkPU1iJtcsIMCEg1XhfX97MYXdl/3W1U8c2/DzfBYJkvFL7S/KUeweKYAedHu1 N6Kb9WRIhRVNz5l5jTUTVvNP/7sbZfqfZt0HVhgH2Z5bTB5yHwYXuE8a8DT1ZnqL2/ jtQO1ncSt3wYG9iSGbxRtlBecy33qwyfoKD5g8/A= Date: Sat, 5 Oct 2019 17:16:35 +0100 From: Jonathan Cameron To: Gwendal Grignou Cc: 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 08/13] platform: chrome: sensorhub: Add code to spread timestmap Message-ID: <20191005171635.6bbc8bbf@archlinux> In-Reply-To: <20190922175021.53449-9-gwendal@chromium.org> References: <20190922175021.53449-1-gwendal@chromium.org> <20190922175021.53449-9-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 Sun, 22 Sep 2019 10:50:16 -0700 Gwendal Grignou wrote: > EC FIFO can send sensor events in batch. Spread them based on > previous (TSa) and currnet timestamp (TSb) > > EC FIFO iio events > +-----------+ > | TSa | > +-----------+ +---------------------------------------+ > | event 1 | | event 1 | TSb - (TSb - TSa)/n * (n-1) | > +-----------+ +---------------------------------------+ > | event 2 | | event 2 | TSb - (TSb - TSa)/n * (n-2) | > +-----------+ +---------------------------------------+ > | ... | ------> | .... | | > +-----------+ +---------------------------------------+ > | event n-1 | | event 2 | TSb - (TSb - TSa)/n | > +-----------+ +---------------------------------------+ > | event n | | event 2 | TSb | > +-----------+ +---------------------------------------+ > | TSb | > +-----------+ > > Signed-off-by: Gwendal Grignou Looks fine to me and the docs are nice :) Timestamps for batches are always a pita. Reviewed-by: Jonathan Cameron > --- > .../platform/chrome/cros_ec_sensorhub_ring.c | 99 ++++++++++++++++++- > 1 file changed, 96 insertions(+), 3 deletions(-) > > diff --git a/drivers/platform/chrome/cros_ec_sensorhub_ring.c b/drivers/platform/chrome/cros_ec_sensorhub_ring.c > index 8cd533d5542e..48327e80a5a3 100644 > --- a/drivers/platform/chrome/cros_ec_sensorhub_ring.c > +++ b/drivers/platform/chrome/cros_ec_sensorhub_ring.c > @@ -160,6 +160,97 @@ static bool cros_ec_ring_process_event( > return true; > } > > +/* > + * cros_ec_ring_spread_add: Calculate proper timestamps then > + * add to ringbuffer (legacy). > + * > + * If there is a sample with a proper timestamp > + * timestamp | count > + * older_unprocess_out --> TS1 | 1 > + * TS1 | 2 > + * out --> TS1 | 3 > + * next_out --> TS2 | > + * We spread time for the samples [older_unprocess_out .. out] > + * between TS1 and TS2: [TS1+1/4, TS1+2/4, TS1+3/4, TS2]. > + * > + * If we reach the end of the samples, we compare with the > + * current timestamp: > + * > + * older_unprocess_out --> TS1 | 1 > + * TS1 | 2 > + * out --> TS1 | 3 > + * We know have [TS1+1/3, TS1+2/3, current timestamp] > + */ > +static void cros_ec_ring_spread_add( > + struct cros_ec_sensorhub *sensorhub, > + unsigned long sensor_mask, > + s64 current_timestamp, > + struct cros_ec_sensors_ring_sample *last_out) > +{ > + struct cros_ec_sensors_ring_sample *out; > + int i; > + > + for_each_set_bit(i, &sensor_mask, BITS_PER_LONG) { > + s64 older_timestamp; > + s64 timestamp; > + struct cros_ec_sensors_ring_sample *older_unprocess_out = > + sensorhub->ring; > + struct cros_ec_sensors_ring_sample *next_out; > + int count = 1; > + > + for (out = sensorhub->ring; out < last_out; out = next_out) { > + s64 time_period; > + > + next_out = out + 1; > + if (out->sensor_id != i) > + continue; > + > + /* Timestamp to start with */ > + older_timestamp = out->timestamp; > + > + /* find next sample */ > + while (next_out < last_out && next_out->sensor_id != i) > + next_out++; > + > + if (next_out >= last_out) { > + timestamp = current_timestamp; > + } else { > + timestamp = next_out->timestamp; > + if (timestamp == older_timestamp) { > + count++; > + continue; > + } > + } > + > + /* > + * The next sample has a new timestamp, > + * spread the unprocessed samples. > + */ > + if (next_out < last_out) > + count++; > + time_period = div_s64(timestamp - older_timestamp, > + count); > + > + for (; older_unprocess_out <= out; > + older_unprocess_out++) { > + if (older_unprocess_out->sensor_id != i) > + continue; > + older_timestamp += time_period; > + older_unprocess_out->timestamp = > + older_timestamp; > + } > + count = 1; > + /* The next_out sample has a valid timestamp, skip. */ > + next_out++; > + older_unprocess_out = next_out; > + } > + } > + > + /* push the event into the kfifo */ > + for (out = sensorhub->ring; out < last_out; out++) > + cros_sensorhub_send_sample(sensorhub, out); > +} > + > /* > * cros_ec_sensorhub_ring_handler - the trigger handler function > * > @@ -280,9 +371,11 @@ static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub) > } > } > > - /* push the event into the kfifo */ > - for (out = sensorhub->ring; out < last_out; out++) > - cros_sensorhub_send_sample(sensorhub, out); > + /* > + * Spread samples in case of batching, then add them to the ringbuffer. > + */ > + cros_ec_ring_spread_add(sensorhub, sensor_mask, > + current_timestamp, last_out); > > ring_handler_end: > sensorhub->fifo_timestamp[LAST_TS] = current_timestamp;