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=-15.5 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 7E247C433EF for ; Sun, 5 Sep 2021 09:40:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 58A3260EE6 for ; Sun, 5 Sep 2021 09:40:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237177AbhIEJk5 convert rfc822-to-8bit (ORCPT ); Sun, 5 Sep 2021 05:40:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:33180 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229691AbhIEJk4 (ORCPT ); Sun, 5 Sep 2021 05:40:56 -0400 Received: from jic23-huawei (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (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 DFABD60EE6; Sun, 5 Sep 2021 09:39:51 +0000 (UTC) Date: Sun, 5 Sep 2021 10:43:13 +0100 From: Jonathan Cameron To: Miquel Raynal Cc: Lars-Peter Clausen , Thomas Petazzoni , linux-iio@vger.kernel.org, Subject: Re: [PATCH 15/16] iio: adc: max1027: Support software triggers Message-ID: <20210905104313.66a6a59a@jic23-huawei> In-Reply-To: <20210902172100.3200b3b6@xps13> References: <20210818111139.330636-1-miquel.raynal@bootlin.com> <20210818111139.330636-16-miquel.raynal@bootlin.com> <20210830115046.3727ccc4@jic23-huawei> <20210902172100.3200b3b6@xps13> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2 Sep 2021 17:21:00 +0200 Miquel Raynal wrote: > Hi Jonathan, > > Jonathan Cameron wrote on Mon, 30 Aug 2021 11:50:46 > +0100: > > > On Wed, 18 Aug 2021 13:11:38 +0200 > > Miquel Raynal wrote: > > > > > Now that max1027_trigger_handler() has been freed from handling hardware > > > triggers EOC situations, we can use it for what it has been designed in > > > the first place: trigger software originated conversions. > > > > As mentioned earlier, this is not how I'd normally expect this sort of > > case to be handled. I'd be expecting the cnvst trigger to still be calling > > this function and the function to do the relevant check to ensure it > > knows the data is already available in that case. > > I tried to follow your advice and Nuno's regarding this, I hope the new > version will match your expectations (new version coming soon). > However if my changes do not match, I will probably need more guidance > to understand in deep what you suggest. > > > > In other > > > words, when userspace initiates a conversion with a sysfs trigger or a > > > hrtimer trigger, we must do all configuration steps, ie: > > > 1- Configuring the trigger > > > 2- Configuring the channels to scan > > > 3- Starting the conversion (actually done automatically by step 2 in > > > this case) > > > 4- Waiting for the conversion to end > > > 5- Retrieving the data from the ADC > > > 6- Push the data to the IIO core and notify it > > > > > > Add the missing steps to this helper and drop the trigger verification > > > hook otherwise software triggers would simply not be accepted at all. > > > > > > Signed-off-by: Miquel Raynal > > > --- > > > drivers/iio/adc/max1027.c | 26 ++++++++++++++------------ > > > 1 file changed, 14 insertions(+), 12 deletions(-) > > > > > > diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c > > > index 8c5995ae59f2..bb437e43adaf 100644 > > > --- a/drivers/iio/adc/max1027.c > > > +++ b/drivers/iio/adc/max1027.c > > > @@ -413,17 +413,6 @@ static int max1027_debugfs_reg_access(struct iio_dev *indio_dev, > > > return spi_write(st->spi, val, 1); > > > } > > > > > > -static int max1027_validate_trigger(struct iio_dev *indio_dev, > > > - struct iio_trigger *trig) > > > -{ > > > - struct max1027_state *st = iio_priv(indio_dev); > > > - > > > - if (st->trig != trig) > > > - return -EINVAL; > > > - > > > - return 0; > > > -} > > > - > > > static int max1027_set_cnvst_trigger_state(struct iio_trigger *trig, bool state) > > > { > > > struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); > > > @@ -512,7 +501,21 @@ static irqreturn_t max1027_trigger_handler(int irq, void *private) > > > > > > pr_debug("%s(irq=%d, private=0x%p)\n", __func__, irq, private); > > > > > > + ret = max1027_configure_trigger(indio_dev); > > > > I'd not expect to see this ever time. The configuration shouldn't change > > from one call of this function to the next. > > True, this is not needed. > > > > + if (ret) > > > + goto out; > > > + > > > + ret = max1027_configure_chans_to_scan(indio_dev); > > > > This should also not change unless it is also responsible for the 'go' signal. > > If that's true then it is badly named. > > It's responsible for the go signal, I renamed it "configure_and_start". > > However, just for my own understanding, when would I be supposed to > configure the channels requested by the user otherwise? For buffered operation update_scan_mask callback. There is a quirk where that's not called on the buffer disable path because it's not always obvious what to 'reset to'. J > > Thanks, > Miquèl