Re: [PATCH v2 02/22] i2c: acpi: Modify i2c_acpi_get_irq() to use resource

From: Andy Shevchenko
Date: Thu Dec 21 2023 - 09:02:01 EST


On Wed, Dec 20, 2023 at 04:54:16PM -0700, Mark Hasemeyer wrote:
> The i2c_acpi_irq_context structure provides redundant information that
> can be provided with struct resource.
>
> Refactor i2c_acpi_get_irq() to use struct resource instead of struct
> i2c_acpi_irq_context.

Suggested-by?

...

> static int i2c_acpi_add_irq_resource(struct acpi_resource *ares, void *data)
> {
> - struct i2c_acpi_irq_context *irq_ctx = data;
> - struct resource r;
> + struct resource *r = data;

> - if (irq_ctx->irq > 0)
> + if (r->start > 0)
> return 1;

Checking flags is more robust.

if (r->flags)
return 1;

> - if (!acpi_dev_resource_interrupt(ares, 0, &r))
> + if (!acpi_dev_resource_interrupt(ares, 0, r))
> return 1;
>
> - irq_ctx->irq = i2c_dev_irq_from_resources(&r, 1);
> - irq_ctx->wake_capable = r.flags & IORESOURCE_IRQ_WAKECAPABLE;
> + i2c_dev_irq_from_resources(r, 1);
>
> return 1; /* No need to add resource to the list */
> }

...

> + if (IS_ERR_OR_NULL(r))
> + return -EINVAL;

Hmm... Do we expect this to be an error pointer in some cases?

...

> + ret = acpi_dev_get_gpio_irq_resource(adev, NULL, 0, r);
> + if (!ret)
> + return r->start;
>
> - return irq_ctx.irq;
> + return ret;

What's wrong with the standard pattern?

if (ret)
return ret;
...
return ...;

...

> + struct resource r = {0};

'0' is redundant.

...

> + irq = i2c_acpi_get_irq(client, &r);
> + if (irq > 0 && r.flags & IORESOURCE_IRQ_WAKECAPABLE)

Why checking just flags is not enough?

> client->flags |= I2C_CLIENT_WAKE;

--
With Best Regards,
Andy Shevchenko