Hi Robin, On 2019-01-21 15:52, Robin Murphy wrote: > 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 <[email protected]> > Reported-by: Marek Szyprowski <[email protected]> > Fixes: 1874619a7df4 "ARM: dma-mapping: Set proper DMA ops in > arm_iommu_detach_device()" > Tested-by: Tobias Jakobi <[email protected]> > Signed-off-by: Robin Murphy <[email protected]> > --- > > Sorry for the delay - there was a giant email infrastructure cock-up just > at the point I wanted to go back through my archive and double-check the > discussion around the original commit...
No problem, could you also upload it to rmk's patch tracking system? IMHO rmk's tree will be the best place to handle this fix. > Robin. > > 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); > } Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
