On Wed, Feb 26, 2025 at 10:57:00AM -0800, Nicolin Chen wrote: > OK, I see. But we are also changing the behavior for the > !CONFIG_IOMMU_DMA configuration, in which case all other iommu > functions seem to return -ENODEV. And I assume we would need a > justification for such a change? > > Perhaps, this can be explicit, just to keep the consistency: > /* NOP if IOMMU driver reports SW_MSI reserved regions */ > return IS_ENABLED(CONFIG_IOMMU_DMA) ? 0 : -ENODEV; Hurm, I donno, if we don't have a IRQ driver that supports it then it doesn't matter that IOMMU_DMA is off either because there is nothing that would call into IOMMU_DMA in the first place. Success still seems like the right answer on such a weirdo kconfig. Jason