Hi Russell, On Thursday 25 May 2017 16:05:41 Russell King - ARM Linux wrote: > On Wed, May 24, 2017 at 02:26:13PM +0300, Laurent Pinchart wrote: > > Again, the patch I propose is the simplest v4.12-rc fix I can think of, > > short of reverting your complete IOMMU probe deferral patch series. Let's > > focus on the v4.12-rc fix, and then discuss how to move forward in v4.13 > > and beyond. > > Except, I don't think it fixes the problem that Sricharan is trying to > fix, namely that of DMA ops that have been setup, torn down, and are > trying to be re-setup again. You're right, it's two separate problems, and we need to fix them both. > The issue here is that results in a stale setup, because the dma_ops are > left in-place from the first iommu setup, but the iommu mapping has been > disposed of. > > Your patch only avoids the problem of tearing down someone else's DMA > ops. We need a combination of both patches together. Yes exactly. I should read e-mails to the end before starting typing the reply :-) > What needs to happen for Sricharan's problem to be resolved is: > > 1. move all of __arm_iommu_detach_device() into arm_iommu_detach_device(). > 2. replace the __arm_iommu_detach_device() call in > arm_teardown_iommu_dma_ops() with arm_iommu_detach_device(). > > as I don't see any need to have a different order in > arm_teardown_iommu_dma_ops(). -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
