On Wed, 22 May 2019 16:36:26 -0400 Qian Cai <[email protected]> wrote: > The commit cf04eee8bf0e ("iommu/vt-d: Include ACPI devices in iommu=pt") > added for_each_active_iommu() in iommu_prepare_static_identity_mapping() > but never used the each element, i.e, "drhd->iommu". > > drivers/iommu/intel-iommu.c: In function > 'iommu_prepare_static_identity_mapping': > drivers/iommu/intel-iommu.c:3037:22: warning: variable 'iommu' set but > not used [-Wunused-but-set-variable] > struct intel_iommu *iommu; > > Fixed the warning by passing "drhd->iommu" directly to > for_each_active_iommu() which all subsequent self-assignments should be > ignored by a compiler anyway. >
Yes, assigning drhd->iommu to itself seems a bit nasty. Maybe this is a case for __mabe_unused (with a comment explaining why), if that fixes the warning. Dunno. btw, for_each_active_dev_scope() and for_each_dev_scope() should be dragged out and shot. Or at least, should have those single-char identifiers changed into something meaningful so poor sods like me have a hope of understanding the code :(
