Received-SPF: pass (google.com: domain of linux-kernel+bounces-204969-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Date: Thu, 6 Jun 2024 17:10:04 -0300
From: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
To: Mark Brown <broonie@kernel.org>
Cc: Nuno =?iso-8859-1?Q?S=E1?= <noname.nuno@gmail.com>,
	Marcelo Schmitt <marcelo.schmitt@analog.com>, lars@metafoo.de,
	Michael.Hennerich@analog.com, jic23@kernel.org, robh+dt@kernel.org,
	krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
	nuno.sa@analog.com, dlechner@baylibre.com,
	linux-iio@vger.kernel.org, devicetree@vger.kernel.org,
	linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 1/6] spi: Add SPI mode bit for MOSI idle state
 configuration
Message-ID: <ZmIXnBSk7nlviIZ3@debian-BULLSEYE-live-builder-AMD64>
References: <cover.1717539384.git.marcelo.schmitt@analog.com>
 <e1d5d57f7a7481c84f64a764f9898122e278739b.1717539384.git.marcelo.schmitt@analog.com>
 <21d3314355b43ecd6acc42f9dfedec501418332d.camel@gmail.com>
 <67f94cfb-6a33-4390-8032-a942f5f7b944@sirena.org.uk>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <67f94cfb-6a33-4390-8032-a942f5f7b944@sirena.org.uk>

On 06/05, Mark Brown wrote:
> On Wed, Jun 05, 2024 at 11:14:33AM +0200, Nuno S? wrote:
> > On Tue, 2024-06-04 at 19:41 -0300, Marcelo Schmitt wrote:
> 
> > > +	/* Check against conflicting MOSI idle configuration */
> > > +	if ((spi->mode & SPI_MOSI_IDLE_LOW) && (spi->mode &
> > > SPI_MOSI_IDLE_HIGH)) {
> > > +		dev_warn(&spi->dev,
> > > +			 "setup: erratic MOSI idle configuration. Set to idle
> > > low\n");
> > > +		spi->mode &= ~SPI_MOSI_IDLE_HIGH;
> > > +	}
> 
> > Should we assume such a thing? IOW, should this be treated as a warning or a
> > real error? I would assume this should be a configuration error and return -
> > EINVAL but...
> 
> Right, and the error message isn't very clear.

Yeah, the message is not all that clear. I'll think of something better.
I'm biased towards having this as a warning because I don't see this as a
feature of usual SPI protocol but not really sure about either ...