> From: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx> > 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
