On Mon, Jun 17, 2024 at 03:33:59PM +0100, Richard Fitzgerald wrote: > On 17/06/2024 15:04, Mark Brown wrote: > > 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. Some of the arm platforms were also an issue in the past, though possibly they've all been modernised by now. Don't know about other older architectures. > 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. Yes, the question was specifically about the assumption that 0 is invalid. The status of 0 is kind of a mess, people keep assuming that it isn't valid and it just depends if users of platforms which try to use 0 trip up over it. Sometimes people work on trying to eliminate uses of 0 but it tends to get you into older code nobody wants to touch. > The kerneldoc for SPI says: > * @irq: Negative, or the number passed to request_irq() to receive > * interrupts from this device. Which includes the 0 as valid thing...
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