Re: [PATCH rc v6 7/7] iommu/arm-smmu-v3: Detect ARM_SMMU_OPT_KDUMP_ADOPT in probe()

[Nicolin Chen]

On Mon, Jun 29, 2026 at 04:40:21PM +0000, Pranjal Shrivastava wrote:
> On Wed, May 20, 2026 at 10:03:24AM -0700, Nicolin Chen wrote:
> > +static void arm_smmu_device_hw_probe_kdump(struct arm_smmu_device *smmu)
> > +{
> > +	u32 gerror, gerrorn, active;
> > +
> > +	/* No adoption if SMMU is disabled (i.e., there is no in-flight DMA) */
> > +	if (!(readl_relaxed(smmu->base + ARM_SMMU_CR0) & CR0_SMMUEN))
> > +		return;
> > +
> > +	/* For now, only support a coherent SMMU that works with MEMREMAP_WB */
> > +	if (!(smmu->features & ARM_SMMU_FEAT_COHERENCY)) {
> > +		dev_warn(smmu->dev,
> > +			 "kdump: non-coherent SMMU unsupported; reset to block all DMAs\n");
> > +		return;
> > +	}
> 
> We seem to be checking it here right at the beginning, let's remove the
> redundant checks downstream?

Seems there is one redundancy. I can drop them.

Thanks
Nicolin