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 3F316C433FE for ; Mon, 7 Nov 2022 07:22:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230095AbiKGHWJ (ORCPT ); Mon, 7 Nov 2022 02:22:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230464AbiKGHWI (ORCPT ); Mon, 7 Nov 2022 02:22:08 -0500 Received: from smtp1.axis.com (smtp1.axis.com [195.60.68.17]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 09129EA for ; Sun, 6 Nov 2022 23:22:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=axis.com; q=dns/txt; s=axis-central1; t=1667805727; x=1699341727; h=date:to:cc:subject:message-id:references:mime-version: content-transfer-encoding:in-reply-to:from; bh=IzfKSEWu4Y0k1DZ/4wrrb9jyMbhuXKqeYYieOjcIBN4=; b=LpVE93y8LqDJ6lDCj+XVZK5MTBlz2wbviHTy5I7K8bPKsLEg0+IbiB29 8wNOYTKUU1P5+GzKuzWKNHEGi2/0LqPNzxHgGllN4hghjmN59S9ehEt+u N+MV96XyP3rBzQ+yBXDa3JNZ+IRtGb3d7jMe6bNqJSp/SeFJSpkSOQonc aJhNDaP9qJWwV0npEek6JFErNhXUmeCr5E/t401U4PM7TO4STPtMBEFUJ xrjmx8UFR7uKc71gyVDOTFQ2414S7qu9rRaQNlOVl7AeOHYkTpfSjgtj7 eqhZ6HITNHlQl79cmO2U6iVEV28tSkYPklJ7dDCnSPUl/f4iRjX2gvEg/ Q==; Date: Mon, 7 Nov 2022 08:22:05 +0100 To: Jonathan Cameron CC: =?iso-8859-1?Q?M=E5rten?= Lindahl , Lars-Peter Clausen , "linux-iio@vger.kernel.org" , kernel , Sudeep Holla Subject: Re: [PATCH] iio: light: vcnl4000: Don't create sysfs PM nodes for child Message-ID: References: <20221101122151.221029-1-marten.lindahl@axis.com> <20221106152307.4bfb4e49@jic23-huawei> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20221106152307.4bfb4e49@jic23-huawei> From: Marten Lindahl Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Sun, Nov 06, 2022 at 04:23:07PM +0100, Jonathan Cameron wrote: > On Tue, 1 Nov 2022 13:21:51 +0100 > Mårten Lindahl wrote: > > > PM runtime is enabled for the parent i2c device, but it is disabled for > > the iio child device and remains so in this driver. But as the child > > sysfs PM directory is created by default by iio_device_register => > > cdev_device_add => dpm_sysfs_add it doesn't bring any value exposing it > > since it won't give any usable data for the user. > > > > Tell dpm_sysfs to not create the PM directory for the iio device. > > > > Signed-off-by: Mårten Lindahl > > Ah this one.. +CC Sudeep who I am sure has considered such changes in other > similar cases (he did the original ones that mean this infastructure exists). > > So, the problem here is that it drops an ABI that has existed in IIO for > a long time. I fully admit the ABI is confusing and pointless. What > I'm not sure on is that we are entirely safe to remove it. > > If we are going to do this, it shouldn't be on a per driver basis, but rather > a global change for all IIO drivers with the proviso that we are relying on > the 'if no one notices an ABI change, it is fine' exception to never changing > userspace ABI. > > Until now this has more or less only been used for new subsystems or where > there were warnings generated due to spurious interface usage in normal flows. > > In IIO, nothing should touch these and I 'think' they don't do anything if > anyone pokes them. > > Jonathan Hi Jonathan! Thanks. I'll drop this change then. Kind regards Mårten > > > > --- > > drivers/iio/light/vcnl4000.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c > > index f6c83ecaad8b..400dc1155559 100644 > > --- a/drivers/iio/light/vcnl4000.c > > +++ b/drivers/iio/light/vcnl4000.c > > @@ -1072,6 +1072,7 @@ static int vcnl4000_probe(struct i2c_client *client, > > if (ret < 0) > > goto fail_poweroff; > > > > + device_set_pm_not_required(&indio_dev->dev); > > ret = iio_device_register(indio_dev); > > if (ret < 0) > > goto fail_poweroff; >