Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <20190822211514.19288-1-olteanv@gmail.com> <20190822211514.19288-6-olteanv@gmail.com>
 <CA+h21hqWGDCfTg813W1WaXFnRsMdE30WnaXw5TJvpkSp0-w5JA@mail.gmail.com>
 <20190827180502.GF23391@sirena.co.uk> <CA+h21hr3qmTG1LyWsEp+hZZW2NJFtg9Dh1k6SXVDd+A_YSQjjw@mail.gmail.com>
 <20190827181318.GG23391@sirena.co.uk>
In-Reply-To: <20190827181318.GG23391@sirena.co.uk>
From:   Vladimir Oltean <olteanv@gmail.com>
Date:   Tue, 27 Aug 2019 21:16:39 +0300
Message-ID: <CA+h21hqMVdsUjBdtiHKtKGpyvuaOf25tc4h-GdDEBQqa3EB7tw@mail.gmail.com>
Subject: Re: [PATCH v2 5/5] ARM: dts: ls1021a-tsn: Use the DSPI controller in
 poll mode
To:     Mark Brown <broonie@kernel.org>
Cc:     linux-spi@vger.kernel.org, lkml <linux-kernel@vger.kernel.org>,
        devicetree@vger.kernel.org, netdev <netdev@vger.kernel.org>,
        Rob Herring <robh@kernel.org>, Shawn Guo <shawnguo@kernel.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Tue, 27 Aug 2019 at 21:13, Mark Brown <broonie@kernel.org> wrote:
>
> On Tue, Aug 27, 2019 at 09:06:14PM +0300, Vladimir Oltean wrote:
> > On Tue, 27 Aug 2019 at 21:05, Mark Brown <broonie@kernel.org> 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.