On Fri, May 01, 2020 at 05:40:41PM -0500, Bjorn Helgaas wrote: > From: Bjorn Helgaas <bhelg...@google.com> > > These interfaces return a negative error number or an IRQ: > > platform_get_irq() > platform_get_irq_optional() > platform_get_irq_byname() > platform_get_irq_byname_optional() > > The function comments suggest checking for error like this: > > irq = platform_get_irq(...); > if (irq < 0) > return irq; > > which is what most callers (~900 of 1400) do, so it's implicit that IRQ 0 > is invalid. But some callers check for "irq <= 0", and it's not obvious > from the source that we never return an IRQ 0. > > Make this more explicit by updating the comments to say that an IRQ number > is always non-zero and adding a WARN() if we ever do return zero. If we do > return IRQ 0, it likely indicates a bug in the arch-specific parts of > platform_get_irq().
I worry about adding WARN() as there are systems that do panic_on_warn() and syzbot trips over this as well. I don't think that for this issue it would be a problem, but what really is this warning about that someone could do anything with? Other than that minor thing, this looks good to me, thanks for finally clearing this up. greg k-h
