Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
Date:   Sat, 19 Mar 2022 17:13:46 +0200
From:   Aaro Koskinen <aaro.koskinen@iki.fi>
To:     Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Oleksij Rempel <o.rempel@pengutronix.de>,
        linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [BISECTED] input: ads7846: touchscreen broken on Nokia 770
Message-ID: <20220319151346.GE1986@darkstar.musicnaut.iki.fi>
References: <20220227185038.GA3016@darkstar.musicnaut.iki.fi>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220227185038.GA3016@darkstar.musicnaut.iki.fi>
Precedence: bulk

Hi,

On Sun, Feb 27, 2022 at 08:50:39PM +0200, Aaro Koskinen wrote:
> I noticed touchscreen does not work anymore on Nokia 770:
> 
> [    2.131011] ads7846 spi2.0: touchscreen, irq 175
> [    2.200622] input: ADS7846 Touchscreen as /devices/platform/omap_uwire/spi_master/spi2/spi2.0/input/input0
> 
> (then touching the screen:)
> 
> [   52.316894] ads7846 spi2.0: spi_sync --> -22
> [   52.336944] ads7846 spi2.0: spi_sync --> -22
> 
> bisected this to:
> 
> commit 9c9509717b53e701469493a8d87ed42c7d782502
> Author: Oleksij Rempel <o.rempel@pengutronix.de>
> Date:   Wed Nov 11 16:39:05 2020 -0800
> 
>     Input: ads7846 - convert to full duplex
> 
> It seems it's failing on SPI_CONTROLLER_HALF_DUPLEX check in
> __spi_validate(). The controller used on this board (spi-omap-uwire)
> sets that flag. How ads7846 is now supposed to work in that case after
> this conversion?

Any comments?

The touchscreen works after reverting the following patches:

6965eece2a89 ("Input: ads7846 - convert to one message")
9c9509717b53 ("Input: ads7846 - convert to full duplex")

A.