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Date: Wed, 05 Jun 2024 15:48:20 +0200
From: Kamel BOUHARA <kamel.bouhara@bootlin.com>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>, Krzysztof Kozlowski
 <krzysztof.kozlowski+dt@linaro.org>, Conor Dooley <conor+dt@kernel.org>,
 Henrik Rydberg <rydberg@bitmath.org>, linux-input@vger.kernel.org,
 linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Marco Felsch
 <m.felsch@pengutronix.de>, Jeff LaBundy <jeff@labundy.com>,
 catalin.popescu@leica-geosystems.com, mark.satterthwaite@touchnetix.com,
 Thomas Petazzoni <thomas.petazzoni@bootlin.com>, Gregory Clement
 <gregory.clement@bootlin.com>, bsp-development.geo@leica-geosystems.com
Subject: Re: [PATCH v13 3/3] Input: Add TouchNetix axiom i2c touchscreen
 driver
In-Reply-To: <20240605124746.GA57733@tpx1.home>
References: <20240603153929.29218-1-kamel.bouhara@bootlin.com>
 <20240603153929.29218-4-kamel.bouhara@bootlin.com>
 <Zl5ZmYyntq7OJOvZ@google.com> <20240605124746.GA57733@tpx1.home>
Message-ID: <7ca4a22f903313128de5c0f65a49b319@bootlin.com>
Organization: Bootlin
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[...]

>> > +
>> > +	error = devm_request_threaded_irq(dev, client->irq, NULL,
>> > +					  axiom_irq, IRQF_ONESHOT, dev_name(dev), ts);
>> > +	if (error) {
>> > +		dev_info(dev, "Request irq failed, falling back to polling mode");
>> 
>> I do not think you should fall back to polling mode if you fail to get
>> interrupt. If it was not specified (client->irq) then I can see that 
>> we
>> might want to fall back, but if the system configured for using
>> interrupt and you can not get it you should bail out.
>> 
> 
> Yes, clear, the polling mode can be decorrelated to the irq not 
> provided
> case.

Just to make sure I understood, is this what you propose ?

if (client->irq) {
         error = devm_request_threaded_irq(...)
         if (error) {
		dev_warn(dev, "failed to request IRQ\n");
		client->irq = 0;
          }
}

if(!client->irq) {
     // setup polling stuff
     ...
}

--
Kamel Bouhara, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com