Hi Zhen Lei, On Mon, Mar 18, 2019 at 09:12:41PM +0800, Zhen Lei wrote: > v1 --> v2: > 1. Drop part2. Now, we only use the SMMUv3 hardware feature STE.config=0b000 > (Report abort to device, no event recorded) to suppress the event messages > caused by the unexpected devices. > 2. rewrite the patch description.
This issue came up a while back: https://lore.kernel.org/linux-pci/20180302103032.gb19...@arm.com/ and I'd still prefer to solve it using the disable_bypass logic which we already have. Something along the lines of the diff below? We're relying on the DMA API not subsequently requesting a passthrough domain, but it should only do that if you've configured your crashkernel to do so. Will --->8 diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index d3880010c6cf..91b8f3b2ee25 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -2454,13 +2454,9 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass) /* Clear CR0 and sync (disables SMMU and queue processing) */ reg = readl_relaxed(smmu->base + ARM_SMMU_CR0); if (reg & CR0_SMMUEN) { - if (is_kdump_kernel()) { - arm_smmu_update_gbpa(smmu, GBPA_ABORT, 0); - arm_smmu_device_disable(smmu); - return -EBUSY; - } - dev_warn(smmu->dev, "SMMU currently enabled! Resetting...\n"); + WARN_ON(is_kdump_kernel() && !disable_bypass); + arm_smmu_update_gbpa(smmu, GBPA_ABORT, 0); } ret = arm_smmu_device_disable(smmu); _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
