From patchwork Tue Jul 26 09:05:49 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Stein X-Patchwork-Id: 9247935 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 554AC60757 for ; Tue, 26 Jul 2016 09:07:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 419F52621E for ; Tue, 26 Jul 2016 09:07:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 32C0926B39; Tue, 26 Jul 2016 09:07:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6A0102621E for ; Tue, 26 Jul 2016 09:07:49 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bRyJh-0006k4-MQ; Tue, 26 Jul 2016 09:06:21 +0000 Received: from webbox1416.server-home.net ([77.236.96.61]) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bRyJd-0006cw-S9 for linux-arm-kernel@lists.infradead.org; Tue, 26 Jul 2016 09:06:19 +0000 Received: from imapserver.systec-electronic.com (unknown [212.185.67.146]) by webbox1416.server-home.net (Postfix) with ESMTPA id 9DCAD27A544; Tue, 26 Jul 2016 11:05:55 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by imapserver.systec-electronic.com (Postfix) with ESMTP id 0DD82DA0A56; Tue, 26 Jul 2016 11:05:55 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at imapserver.systec-electronic.com Received: from imapserver.systec-electronic.com ([127.0.0.1]) by localhost (imapserver.systec-electronic.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id mcboEj_2bYC0; Tue, 26 Jul 2016 11:05:52 +0200 (CEST) Received: from ws-stein.localnet (ws-stein.systec.local [192.168.10.117]) by imapserver.systec-electronic.com (Postfix) with ESMTPA id 54E04DA0A43; Tue, 26 Jul 2016 11:05:52 +0200 (CEST) From: Alexander Stein To: Quentin Schulz Subject: Re: [PATCH v3 1/4] hwmon: iio_hwmon: delay probing with late_initcall Date: Tue, 26 Jul 2016 11:05:49 +0200 Message-ID: <5277864.qlyRKbC1Zy@ws-stein> User-Agent: KMail/4.14.10 (Linux/4.6.0-gentoo; KDE/4.14.20; x86_64; ; ) In-Reply-To: <10d14cc4-26f1-8f2d-2997-3b2bc323c40e@free-electrons.com> References: <1469519027-11387-1-git-send-email-quentin.schulz@free-electrons.com> <209942367.uny0GxrY2s@ws-stein> <10d14cc4-26f1-8f2d-2997-3b2bc323c40e@free-electrons.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160726_020618_167287_F010E6B3 X-CRM114-Status: GOOD ( 13.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-hwmon@vger.kernel.org, thomas.petazzoni@free-electrons.com, lars@metafoo.de, linux-iio@vger.kernel.org, antoine.tenart@free-electrons.com, linux-kernel@vger.kernel.org, wens@csie.org, jdelvare@suse.com, linux@roeck-us.net, pmeerw@pmeerw.net, knaack.h@gmx.de, maxime.ripard@free-electrons.com, lee.jones@linaro.org, jic23@kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP On Tuesday 26 July 2016 10:24:48, Quentin Schulz wrote: > On 26/07/2016 10:21, Alexander Stein wrote: > > On Tuesday 26 July 2016 09:43:44, Quentin Schulz wrote: > >> iio_channel_get_all returns -ENODEV when it cannot find either phandles > >> and > >> properties in the Device Tree or channels whose consumer_dev_name matches > >> iio_hwmon in iio_map_list. The iio_map_list is filled in by iio drivers > >> which might be probed after iio_hwmon. > > > > Would it work if iio_channel_get_all returning ENODEV is used for > > returning > > EPROBE_DEFER in iio_channel_get_all? Using late initcalls for > > driver/device > > dependencies seems not right for me at this place. > > Then what if the iio_channel_get_all is called outside of the probe of a > driver? We'll have to change the error code, things we are apparently > trying to avoid (see v2 patches' discussions). Maybe I didn't express my idea enough. I don't want to change the behavior of iio_channel_get_all at all. Just the result evaluation of iio_channel_get_all in iio_hwmon_probe. I have something link the patch below in mind. Best regards, Alexander diff --git a/drivers/hwmon/iio_hwmon.c b/drivers/hwmon/iio_hwmon.c index b550ba5..e32d150 100644 --- a/drivers/hwmon/iio_hwmon.c +++ b/drivers/hwmon/iio_hwmon.c @@ -73,8 +73,12 @@ static int iio_hwmon_probe(struct platform_device *pdev) name = dev->of_node->name; channels = iio_channel_get_all(dev); - if (IS_ERR(channels)) - return PTR_ERR(channels); + if (IS_ERR(channels)) { + if (PTR_ERR(channels) == -ENODEV) + return -EPROBE_DEFER; + else + return PTR_ERR(channels); + } st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); if (st == NULL) {