RE: [PATCH rc v1 3/4] iommu/arm-smmu-v3: Retain SMMUEN during kdump device reset

Tian, Kevin
2026-04-10T06:21:47Z

> From: Nicolin Chen <nicolinc@nvidia.com>
> Sent: Friday, April 10, 2026 3:47 AM
>
> /* Clear CR0 and sync (disables SMMU and queue processing) */
> reg = readl_relaxed(smmu->base + ARM_SMMU_CR0);
> if (reg & CR0_SMMUEN) {
> dev_warn(smmu->dev, "SMMU currently enabled!
> Resetting...\n");

move to after the check of kdump kernel

> @@ -5038,6 +5064,11 @@ static int arm_smmu_device_reset(struct
> arm_smmu_device *smmu)
> return ret;
> }
>
> + /*
> + * Disable EVTQ and PRIQ in kdump kernel. The old kernel's CDs and
> page
> + * tables may be corrupted, which could trigger event spamming.
> PRIQ is
> + * also useless since we cannot service page requests during kdump.
> + */
> if (is_kdump_kernel())
> enables &= ~(CR0_EVTQEN | CR0_PRIQEN);
>

then just don't enable them in earlier lines?