From fc67e6f120a388b611d94cc40baf99a5cc56b283 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Wed, 6 Feb 2019 18:43:24 +0100 Subject: [PATCH] ARM: 8835/1: dma-mapping: Clear DMA ops on teardown Installing the appropriate non-IOMMU DMA ops in arm_iommu_detch_device() serves the case where IOMMU-aware drivers choose to control their own mapping but still make DMA API calls, however it also affects the case when the arch code itself tears down the mapping upon driver unbinding, where the ops now get left in place and can inhibit arch_setup_dma_ops() on subsequent re-probe attempts. Fix the latter case by making sure that arch_teardown_dma_ops() cleans up whenever the ops were automatically installed by its counterpart. Reported-by: Tobias Jakobi Reported-by: Marek Szyprowski Fixes: 1874619a7df4 "ARM: dma-mapping: Set proper DMA ops in arm_iommu_detach_device()" Tested-by: Tobias Jakobi Tested-by: Thierry Reding Signed-off-by: Robin Murphy Signed-off-by: Russell King --- arch/arm/mm/dma-mapping.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index f1e2922e447c..1e3e08a1c456 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -2390,4 +2390,6 @@ void arch_teardown_dma_ops(struct device *dev) return; arm_teardown_iommu_dma_ops(dev); + /* Let arch_setup_dma_ops() start again from scratch upon re-probe */ + set_dma_ops(dev, NULL); }