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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A67DEC433EF for ; Tue, 22 Mar 2022 20:34:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233969AbiCVUdy (ORCPT ); Tue, 22 Mar 2022 16:33:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35544 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233857AbiCVUdt (ORCPT ); Tue, 22 Mar 2022 16:33:49 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 322A7F11; Tue, 22 Mar 2022 13:32:21 -0700 (PDT) Received: from fraeml707-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4KNNQR0mwHz6H7Kg; Wed, 23 Mar 2022 04:30:07 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml707-chm.china.huawei.com (10.206.15.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 22 Mar 2022 21:32:19 +0100 Received: from localhost (10.47.75.191) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Tue, 22 Mar 2022 20:32:18 +0000 Date: Tue, 22 Mar 2022 20:32:16 +0000 From: Jonathan Cameron To: Andrea Merello CC: Jonathan Cameron , Mauro Carvalho Chehab , linux-iio , linux-kernel , devicetree , Lars-Peter Clausen , "Rob Herring" , Andy Shevchenko , Matt Ranostay , Alexandru Ardelean , Jacopo Mondi , Andrea Merello Subject: Re: [v3 13/13] docs: iio: add documentation for BNO055 driver Message-ID: <20220322203216.0000141f@Huawei.com> In-Reply-To: References: <20220217162710.33615-1-andrea.merello@gmail.com> <20220217162710.33615-14-andrea.merello@gmail.com> <20220219170645.565afed8@jic23-huawei> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.29; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.47.75.191] X-ClientProxiedBy: lhreml742-chm.china.huawei.com (10.201.108.192) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 22 Mar 2022 11:30:12 +0100 Andrea Merello wrote: > [...] > > > > +IIO attributes for unavailable measurements (e.g. Euler angles when fusion > > > +mode is disabled) just read zero. > > > > Hmm. Should probably return -EBUSY as 0 could be a valid value. > > > > While it seems reasonable, that can be easily done while reading from > sysfs, but how do we handle this when reading from buffer? > Right now both sysfs and buffer read zero from unused chans, which it > is at least consistent.. Can't we refuse to start the buffer if we have a channel enabled that makes no sense in the current mode? If seems very odd to allow capture of 'nothing'. Jonathan