RE: [PATCH] ASoC: cs35l56: Accept values greater than 0 as IRQ numbers

[Simon Trimmer <simont@opensource.cirrus.com>]

> From: Richard Fitzgerald <rf@opensource.cirrus.com>
> Sent: Monday, June 17, 2024 3:34 PM
> On 17/06/2024 15:04, Mark Brown wrote:
> > On Mon, Jun 17, 2024 at 02:53:38PM +0100, Simon Trimmer wrote:
> >> IRQ lookup functions such as those in ACPI can return error values when
> >> an IRQ is not defined. The i2c core driver converts the error codes to
a
> >> value of 0 and the SPI bus driver passes them unaltered to client
device
> >> drivers.
> >>
> >> The cs35l56 driver should only accept positive non-zero values as IRQ
> >> numbers.
> >
> > Have all architectures removed 0 as a valid IRQ?
> 
>  From discussion threads we can find 0 might still used on x86 for a
> legacy device.
> But the conversations we can find on this don't seem to exclude passing
> a negative error number, just that 0 can normally be assumed invalid.
> 
> The kerneldoc for SPI says:
> 
>   * @irq: Negative, or the number passed to request_irq() to receive
>   *	interrupts from this device.

Yes and the threads of these lore links in these commits are rather feisty

ce753ad1549c platform: finally disallow IRQ0 in platform_get_irq() and its
ilk
a85a6c86c25b driver core: platform: Clarify that IRQ 0 is invalid