From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTP id 9EEAB9A0 for ; Mon, 5 May 2014 08:54:20 +0000 (UTC) Received: from e23smtp04.au.ibm.com (e23smtp04.au.ibm.com [202.81.31.146]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id D5885201BB for ; Mon, 5 May 2014 08:54:18 +0000 (UTC) Received: from /spool/local by e23smtp04.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 5 May 2014 18:44:09 +1000 Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [9.190.235.21]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id AAB982BB0040 for ; Mon, 5 May 2014 18:44:05 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s458hoC43473828 for ; Mon, 5 May 2014 18:43:50 +1000 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s458i4Cg006472 for ; Mon, 5 May 2014 18:44:05 +1000 Message-ID: <1399279435.20388.36.camel@pasglop> From: Benjamin Herrenschmidt To: "Rafael J. Wysocki" Date: Mon, 05 May 2014 18:43:55 +1000 In-Reply-To: <1753987.hbb65qFWcl@vostro.rjw.lan> References: <20140504111436.GC15180@arm.com> <20140504171807.GA4418@quad.lixom.net> <1753987.hbb65qFWcl@vostro.rjw.lan> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Cc: Greg Kroah-Hartman , "dvhart@dvhart.com" , "Rafael J. Wysocki" , ksummit-discuss@lists.linuxfoundation.org Subject: Re: [Ksummit-discuss] [TECH TOPIC] Driver model/resources, ACPI, DT, etc (sigh) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sun, 2014-05-04 at 23:33 +0200, Rafael J. Wysocki wrote: > > > But we have such quirks for some bus types already, like PCI and PNP. And they suck big time. They duplicate definitions from the driver, they get missed at grep time, they bit rot, etc... There are a few cases where that's justified simply because the driver can be a module but the quirk needs to run early and always, but mostly these quirks are about working around HW bugs that would otherwise cause the system to misbehave even in absence of the driver. For example, bad class code in bridges, BAR issues, etc... Generally speaking though, quirks like that are a bad idea and in this case, totally unjustified since the code performing whatever translation is necessary (or interpretation) is entirely specific to the driver anyway. Also if the bindings evolve, you just created a 3rd way dependency. Instead of just having to deal with DT/ACPI binding version vs. driver version, we now have to also handle quirk versioning. Cheers, Ben.