From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935092AbdAFJvZ (ORCPT ); Fri, 6 Jan 2017 04:51:25 -0500 Received: from mail-wm0-f53.google.com ([74.125.82.53]:38715 "EHLO mail-wm0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763999AbdAFJuU (ORCPT ); Fri, 6 Jan 2017 04:50:20 -0500 Date: Fri, 6 Jan 2017 09:53:49 +0000 From: Lee Jones To: Bjorn Andersson Cc: Rob Herring , Mark Rutland , Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Richard Purdie , Jacek Anaszewski , Pavel Machek , Jingoo Han , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, linux-leds@vger.kernel.org, Bjorn Andersson Subject: Re: [PATCH v4 2/5] mfd: lm3533: Support initialization from Device Tree Message-ID: <20170106095349.GE9851@dell> References: <20161226181153.11271-1-bjorn.andersson@linaro.org> <20161226181153.11271-2-bjorn.andersson@linaro.org> <20170104115424.GH27589@dell> <20170104192608.GN10531@minitux> <20170105074952.GG24225@dell> <20170105163054.GO10531@minitux> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170105163054.GO10531@minitux> User-Agent: Mutt/1.6.2 (2016-07-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 05 Jan 2017, Bjorn Andersson wrote: > On Wed 04 Jan 23:49 PST 2017, Lee Jones wrote: > > > On Wed, 04 Jan 2017, Bjorn Andersson wrote: > > > > > On Wed 04 Jan 03:54 PST 2017, Lee Jones wrote: > > > > > > > On Mon, 26 Dec 2016, Bjorn Andersson wrote: > > > > > > > > > From: Bjorn Andersson > > > > > > > > > > Implement support for initialization of the lm3533 driver core and > > > > > probing child devices from Device Tree. > > > > > > > > > > > [..] > > > > > > > > @@ -512,6 +514,11 @@ static int lm3533_device_init(struct lm3533 *lm3533) > > > > > lm3533_device_bl_init(lm3533); > > > > > lm3533_device_led_init(lm3533); > > > > > > > > > > + if (lm3533->dev->of_node) { > > > > > + of_platform_populate(lm3533->dev->of_node, NULL, NULL, > > > > > + lm3533->dev); > > > > > + } > > > > > > > > I think it's save to call of_platform_populate(), even if !of_node. > > > > It will just fail and return an error code, which you are ignoring > > > > anyway. > > > > > > > > > > I thought so too, but that's apparently how you trigger probing children > > > of the root node. So we're stuck with a conditional. > > > > Ah, so this is to protect against the case where DT is present, but a > > node for this device is not (or is disabled), so is left unprobed. > > Then the bind is initiated via I2C? Or something else? > > > > In the event that a new lm3533 is spawned from sysfs we would not have > platform_data when entering lm3533_device_init() and just bail early. > > Therefor, this issue would be limited to the odd case of lm3533 being > initiated from code (e.g. a board file) on a DT enabled system. In which > case it will create and probe new devices from the root of the DT. Eewww, do we really want to support that? -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog