[PATCH] arm64: Remove pointless WARN_ON in DMA teardown
Sricharan
sricharan at codeaurora.org
Wed Oct 26 19:32:15 PDT 2016
Hi,
>
>We expect arch_teardown_dma_ops() to be called very late in a device's
>life, after it has been removed from its bus, and thus after the IOMMU
>bus notifier has run. As such, even if this funny little check did make
>sense, it's unlikely to achieve what it thinks it's trying to do anyway.
>It's a residual trace of an earlier implementation which didn't belong
>here from the start; belatedly snuff it out.
>
>Signed-off-by: Robin Murphy <robin.murphy at arm.com>
>---
> arch/arm64/mm/dma-mapping.c | 5 -----
> 1 file changed, 5 deletions(-)
>
>diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
>index 5cd0a383b14b..290a84f3351f 100644
>--- a/arch/arm64/mm/dma-mapping.c
>+++ b/arch/arm64/mm/dma-mapping.c
>@@ -940,11 +940,6 @@ static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
>
> void arch_teardown_dma_ops(struct device *dev)
> {
>- struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
>-
>- if (WARN_ON(domain))
>- iommu_detach_device(domain, dev);
>-
Thanks!!, clears my doubt that i had for quite sometime.
Regards,
Sricharan
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