From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757096AbcAYMiR (ORCPT ); Mon, 25 Jan 2016 07:38:17 -0500 Received: from mail.karo-electronics.de ([81.173.242.67]:62328 "EHLO mail.karo-electronics.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756072AbcAYMiP convert rfc822-to-8bit (ORCPT ); Mon, 25 Jan 2016 07:38:15 -0500 Date: Mon, 25 Jan 2016 13:37:31 +0100 From: Lothar =?UTF-8?B?V2HDn21hbm4=?= To: Mark Brown Cc: =?UTF-8?B?QmVub8OudA==?= Cousson , Ian Campbell , Kumar Gala , Liam Girdwood , Mark Rutland , Pawel Moll , Rob Herring , Russell King , Tony Lindgren , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org Subject: Re: [PATCH 1/2] regulator: ltc3589: make IRQ optional Message-ID: <20160125133731.72669115@ipc1.ka-ro> In-Reply-To: <20160122162610.GZ6588@sirena.org.uk> References: <1453292992-1788-1-git-send-email-LW@KARO-electronics.de> <1453292992-1788-2-git-send-email-LW@KARO-electronics.de> <20160120164258.GF6588@sirena.org.uk> <20160121080524.27af489f@ipc1.ka-ro> <20160121102015.GI6588@sirena.org.uk> <20160121112611.34e17cb2@ipc1.ka-ro> <20160121111115.GJ6588@sirena.org.uk> <20160121123311.5346e40d@ipc1.ka-ro> <20160121162646.GK6588@sirena.org.uk> <20160122064145.36b7f2b4@ipc1.ka-ro> <20160122162610.GZ6588@sirena.org.uk> Organization: Ka-Ro electronics GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Fri, 22 Jan 2016 16:26:10 +0000 Mark Brown wrote: > On Fri, Jan 22, 2016 at 06:41:45AM +0100, Lothar Waßmann wrote: > > > On Thu, Jan 21, 2016 at 12:33:11PM +0100, Lothar Waßmann wrote: > > > > Your commit message (quoted above) claims that without this patch if no > > > interrupt is supplied then the unsupplied interrupt will somehow be left > > > screaming and make the system unusable. This doesn't make sense, if > > > there is no interrupt there is nothing to scream. > > > "Otherwise" meant the case where the IRQ is specified in DT as is > > currently required to get the driver loaded at all. > > > > So, contrary to what you've been saying, the interrupt is actually > > > connected (and worse, connected to a NMI) but apparently not described > > > in DT. Why is it sensible to make the driver poll (which will affect > > > all systems using this device, even those that don't care) and not just > > > describe the interrupt in DT so it can be handled promptly in the normal > > > fashion? Presumably this will run into serious problems if the > > > interrupt actually fires at runtime since the NMI will scream, it's not > > > clear to me how the poll will manage to run successfully in that case. > > > Currently the driver won't even load without an IRQ specified in DT. > > My patch makes it possible to use the driver without requiring an IRQ! > > You're not just making the interrupt optional, you are also implementing > polling support. That's really unusual and there's no clear reason for > it, your changelog seems to claim that it is needed to make the system > work but that seems at best very surprising and would need a more > detailed changelog. > > You at least need to provide an understandable changelog, though it > seems it is more likely that there is a more sensible way of dealing > with this. > Any suggestions how to handle this case in a more sensible way? Lothar Waßmann