linux-kernel - Re: [PATCH net-next v6 03/12] net: pse-pd: tps23881: Add support for PSE events and interrupts

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Message-ID: <Z9fu3u34K3-OeDis@pengutronix.de>
Date: Mon, 17 Mar 2025 10:43:58 +0100
From: Oleksij Rempel <o.rempel@...gutronix.de>
To: Kory Maincent <kory.maincent@...tlin.com>
Cc: Andrew Lunn <andrew@...n.ch>, "David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Jonathan Corbet <corbet@....net>,
	Donald Hunter <donald.hunter@...il.com>,
	Rob Herring <robh@...nel.org>, Andrew Lunn <andrew+netdev@...n.ch>,
	Simon Horman <horms@...nel.org>,
	Heiner Kallweit <hkallweit1@...il.com>,
	Russell King <linux@...linux.org.uk>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Liam Girdwood <lgirdwood@...il.com>,
	Mark Brown <broonie@...nel.org>,
	Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
	netdev@...r.kernel.org, linux-doc@...r.kernel.org,
	Kyle Swenson <kyle.swenson@....tech>,
	Dent Project <dentproject@...uxfoundation.org>,
	kernel@...gutronix.de,
	Maxime Chevallier <maxime.chevallier@...tlin.com>,
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH net-next v6 03/12] net: pse-pd: tps23881: Add support for
 PSE events and interrupts

On Tue, Mar 04, 2025 at 11:18:52AM +0100, Kory Maincent wrote:
> +static int tps23881_irq_handler(int irq, struct pse_controller_dev *pcdev,
> +				unsigned long *notifs,
> +				unsigned long *notifs_mask)
> +{
> +	struct tps23881_priv *priv = to_tps23881_priv(pcdev);
> +	struct i2c_client *client = priv->client;
> +	int ret, it_mask;
> +
> +	/* Get interruption mask */
> +	ret = i2c_smbus_read_word_data(client, TPS23881_REG_IT_MASK);
> +	if (ret < 0)
> +		return ret;
> +	it_mask = ret;
> +
> +	/* Read interrupt register until it frees the interruption pin. */
> +	while (true) {

If the hardware has a stuck interrupt, this could result in an infinite
loop. max_retries with some sane value would be good.

> +		ret = i2c_smbus_read_word_data(client, TPS23881_REG_IT);
> +		if (ret < 0)
> +			return ret;
> +
> +		/* No more relevant interruption */
> +		if (!(ret & it_mask))
> +			return 0;
> +
> +		ret = tps23881_irq_event_handler(priv, (u16)ret, notifs,
> +						 notifs_mask);
> +		if (ret)
> +			return ret;
> +	}
> +	return 0;
> +}
> +
> +static int tps23881_setup_irq(struct tps23881_priv *priv, int irq)
> +{
> +	struct i2c_client *client = priv->client;
> +	struct pse_irq_desc irq_desc = {
> +		.name = "tps23881-irq",

here or in devm_pse_irq_helper() it would be good to add intex suffix to
the irq handler name.

v> +		.map_event = tps23881_irq_handler,
> +	};
> +	int ret;
> +	u16 val;
> +
> +	val = TPS23881_REG_IT_IFAULT | TPS23881_REG_IT_SUPF;
> +	val |= val << 8;
> +	ret = i2c_smbus_write_word_data(client, TPS23881_REG_IT_MASK, val);
> +	if (ret)
> +		return ret;
> +
> +	ret = i2c_smbus_read_word_data(client, TPS23881_REG_GEN_MASK);
> +	if (ret < 0)
> +		return ret;
> +
> +	val = (u16)(ret | TPS23881_REG_INTEN | TPS23881_REG_INTEN << 8);
> +	ret = i2c_smbus_write_word_data(client, TPS23881_REG_GEN_MASK, val);
> +	if (ret < 0)
> +		return ret;
> +
> +	return devm_pse_irq_helper(&priv->pcdev, irq, 0, &irq_desc);
> +}
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