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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 CDC54ECDE27 for ; Wed, 11 Sep 2019 06:34:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A430621D79 for ; Wed, 11 Sep 2019 06:34:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568183645; bh=nILqRGanKyWCsHzEVK8odXbwKzmEyjYx6QNVTLEWPxI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=HE+Uw7CdFz87I39HJ9IspzrSm0kyV6KbpXd/BSyOKN+4Pt4vrjqe4Aqg7/FezE1c+ 756OO0zUgjcV5TE2Tgk5XKjwHVfrTlJ1dMroB7H4z2riNfmIwpRsM+bFWA7/UJrJh0 OpeqHcbOlDhxI/bf8Mm18xv+wqqYnUucD4bNTgKE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726927AbfIKGeC (ORCPT ); Wed, 11 Sep 2019 02:34:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:37966 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726390AbfIKGeC (ORCPT ); Wed, 11 Sep 2019 02:34:02 -0400 Received: from dragon (98.142.130.235.16clouds.com [98.142.130.235]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A1F7B21D79; Wed, 11 Sep 2019 06:33:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568183641; bh=nILqRGanKyWCsHzEVK8odXbwKzmEyjYx6QNVTLEWPxI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hdiGnsYABZmVcA3qsJpOxGkwJMtLvaWrreihk580l8Bdua269dMT9TuUPCKFcKfHp +WhR12Ze+NzXy0ixqQA0GNZVk17CK3kfBB3iwU9+hkHQStxz+N0YKHGiymxkG8aSpn NjoHWrIMmv05+LjhyeVwUE8PVyePFUEFqRn7W2hQ= Date: Wed, 11 Sep 2019 14:33:51 +0800 From: Shawn Guo To: Vladimir Oltean Cc: Mark Brown , linux-spi@vger.kernel.org, lkml , devicetree@vger.kernel.org, netdev , Rob Herring Subject: Re: [PATCH v2 5/5] ARM: dts: ls1021a-tsn: Use the DSPI controller in poll mode Message-ID: <20190911063350.GB17142@dragon> References: <20190822211514.19288-1-olteanv@gmail.com> <20190822211514.19288-6-olteanv@gmail.com> <20190827180502.GF23391@sirena.co.uk> <20190827181318.GG23391@sirena.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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. Shawn