Re: [PATCH v1 1/2] drm/xe/i2c: Handler for SMBus Alerts

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Mon, Jun 22, 2026 at 01:47:58PM +0200, Heikki Krogerus wrote:
> Some devices that are attached to the I2C controller use the
> SMBus Alert signal for example to inform the host about
> thermal events, so registering the default SMBus Alert
> device device for them. The alert device makes sure that
> the alert is processed and passed to the correct I2C client
> driver.

...

> +	if (i2c->smbus_alert)

Unneeded. Also the below incorporates error pointer cases.

> +		i2c_unregister_device(i2c->smbus_alert);
> +
>  	if (!i2c->irqdomain)
>  		return;

...

> +++ b/drivers/gpu/drm/xe/xe_i2c_smbus.c
> @@ -0,0 +1,59 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Intel Xe SMBus handling
> + *
> + * Copyright (C) 2026 Intel Corporation.
> + */

+ bits.h // BIT()
+ err.h // IS_ERR()

> +#include <linux/i2c-smbus.h>
> +#include <linux/regmap.h>
> +#include <linux/types.h>

...

> +static struct i2c_smbus_alert_setup xe_i2c_smbus_setup;
> +
> +int xe_i2c_register_smbus_alert(struct xe_i2c *i2c)
> +{
> +	struct i2c_client *alert;
> +
> +	alert = i2c_new_smbus_alert_device(i2c->adapter, &xe_i2c_smbus_setup);
> +	if (IS_ERR(alert))
> +		return PTR_ERR(alert);
> +
> +	i2c->smbus_alert = alert;
> +
> +	return 0;
> +}

As per above comment, this IS_ERR() is not need, as the removal API is optional-aware.
OTOH, the other NULL-check in the driver in that case needs to be IS_ERR_OR_NULL().

But I'm not sure if you want to have alert setup to always succeed.

-- 
With Best Regards,
Andy Shevchenko