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 X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31844ECDE27 for ; Wed, 11 Sep 2019 07:00:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0C92421928 for ; Wed, 11 Sep 2019 07:00:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726814AbfIKHAR (ORCPT ); Wed, 11 Sep 2019 03:00:17 -0400 Received: from mail-ot1-f67.google.com ([209.85.210.67]:37937 "EHLO mail-ot1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725747AbfIKHAR (ORCPT ); Wed, 11 Sep 2019 03:00:17 -0400 Received: by mail-ot1-f67.google.com with SMTP id h17so17717188otn.5; Wed, 11 Sep 2019 00:00:15 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=9dr69d7D9AZxG4ptlvv1ouodNVo3Kf2fAKXXlCgtDP4=; b=BHbwToTOy7gV+Sqb0XdCfOWHFyMJhmRslvW20JdZHukCG9CZIbRgbKr+froKoeNk/q O9QzPQKRgFMNPb6QanP9hz2se6oqURScWVOIsHh6sJ6HKupeLggZvXqdW6VhEhDi4ugW 79tOCiZpgJPz5TZFlYGVv1//3YgpPu6+CVDX5Lz0fuXQREu2Dg1eSHZ99jl6NuoNSdUH CewR+rngrkWwPZ8+EHQZPhqsmkfEg6IGZ29wsaKqWoHPbDUfDs6ED2DyHwEyf7R2AHDL 1MB5cOUZoWjUJn/HaYeN16p/ye54shNwdcU4P8D7xFY3Tnl2lKterZcrOVBoRci7vmud tGAA== X-Gm-Message-State: APjAAAXaukwcNuOE8SU3EttZwyJ+XdscYWOC9iz25+R9CuILV5facJ7e 5ykAMaH0Be7h/vlbp1ZtoBSdGbaivnmp9+mP+vE2BQ== X-Google-Smtp-Source: APXvYqy4nHbGq/yzYGyyJzdHSy/BGAXMkUJgPZNy7UvGhLOxuZGHxNeZq+CTxvohtCCs/uICkjnYAnt9e3O/5m5p1Vo= X-Received: by 2002:a9d:32a1:: with SMTP id u30mr24883499otb.107.1568185215069; Wed, 11 Sep 2019 00:00:15 -0700 (PDT) MIME-Version: 1.0 References: <20190822211514.19288-1-olteanv@gmail.com> <20190822211514.19288-6-olteanv@gmail.com> <20190827180502.GF23391@sirena.co.uk> <20190827181318.GG23391@sirena.co.uk> <20190911063350.GB17142@dragon> In-Reply-To: <20190911063350.GB17142@dragon> From: Geert Uytterhoeven Date: Wed, 11 Sep 2019 09:00:03 +0200 Message-ID: Subject: Re: [PATCH v2 5/5] ARM: dts: ls1021a-tsn: Use the DSPI controller in poll mode To: Shawn Guo Cc: Vladimir Oltean , Mark Brown , linux-spi , lkml , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , netdev , Rob Herring Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Sep 11, 2019 at 8:34 AM Shawn Guo wrote: > On Tue, Aug 27, 2019 at 09:16:39PM +0300, Vladimir Oltean wrote: > > On Tue, 27 Aug 2019 at 21:13, Mark Brown wrote: > > > On Tue, Aug 27, 2019 at 09:06:14PM +0300, Vladimir Oltean wrote: > > > > On Tue, 27 Aug 2019 at 21:05, Mark Brown wrote: > > > > > On Mon, Aug 26, 2019 at 04:10:51PM +0300, Vladimir Oltean wrote: > > > > > > > > > I noticed you skipped applying this patch, and I'm not sure that Shawn > > > > > > will review it/take it. > > > > > > Do you have a better suggestion how I can achieve putting the DSPI > > > > > > driver in poll mode for this board? A Kconfig option maybe? > > > > > > > > DT changes go through the relevant platform trees, not the > > > > > subsystem trees, so it's not something I'd expect to apply. > > > > > > > But at least is it something that you expect to see done through a > > > > device tree change? > > > > > > Well, it's not ideal - if it performs better all the time the > > > driver should probably just do it unconditionally. If there's > > > some threashold where it tends to perform better then the driver > > > should check for that but IIRC it sounds like the interrupt just > > > isn't at all helpful here. > > > > I can't seem to find any situation where it performs worse. Hence my > > question on whether it's a better idea to condition this behavior on a > > Kconfig option rather than a DT blob which may or may not be in sync. > > DT is a description of hardware not condition for software behavior, > where module parameter is usually used for. +1 DT says the interrupt line is wired. The driver should know if it should make use of the interrupt, or not. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds