iommu: remove unnecessary code
PATCH 1/1 iommu: remove unnecessary code
did_old is an unsigned variable and, greater-than-or-equal-to-zero comparison of an unsigned variable is always true.
Addresses-Coverity-ID: 1398477
--- drivers/iommu/intel-iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/iommu/intel-iommu.c +1 -1
@@ -2050,7 +2050,7 @@ static int domain_context_mapping_one(struct dmar_domain *domain,if (context_copied (context)) {u16 did_old =context_domain_id (context); -if (did_old >=0 && did_old <cap_ndoms (iommu->cap)) +if (did_old <cap_ndoms (iommu->cap)) iommu->flush.flush_context(iommu, did_old, (((u16)bus) << 8) | devfn, DMA_CCMD_MASK_NOBIT,
Signature · 1 line
2.5.0
Quoted 5 lines · Gustavo A. R. Silva
did_oldis an unsigned variable and, greater-than-or-equal-to-zero comparison of an unsigned variable is always true.Addresses-Coverity-ID: 1398477
Signed-off-by Gustavo A. R. Silva <garsilva-L1vi/[email protected]>
So... why do you think that check was there? Do you think it's possible that someone mistakenly *thought* it could be negative? What were they actually checking for? Have you actually *fixed* a bug here, or have you just masked it?
Even if you've done all that analysis and it *is* correct just to drop the comparison rather than fixing it, you need to put verbiage to that effect into the commit comment.
Never write patches to "fix warnings". Always to fix bugs.
Quoted 17 lines
---
drivers/iommu/intel-iommu.c | 2 +-1 file changed, 1 insertion(+), 1 deletion(-)drivers/iommu/intel-iommu.c +0
-0@@ -2050,7 +2050,7 @@ static int domain_context_mapping_one(struct dmar_domain *domain, if (context_copied(context)) { u16 did_old = context_domain_id(context);drivers/iommu/intel-iommu.c +1
-1-if (did_old >=0 && did_old <cap_ndoms (iommu->cap)) +if (did_old <cap_ndoms (iommu->cap))iommu->flush.flush_context(iommu,
did_old, (((u16)bus) << 8) | devfn,DMA_CCMD_MASK_NOBIT,