Re: [PATCH rc v6 4/7] iommu/arm-smmu-v3: Skip EVTQ/PRIQ setup in kdump kernel

[Nicolin Chen <nicolinc@nvidia.com>]

On Mon, Jun 29, 2026 at 03:15:21PM +0000, Pranjal Shrivastava wrote:
> On Wed, May 20, 2026 at 10:03:21AM -0700, Nicolin Chen wrote:
> > +	if (!is_kdump_kernel()) {
> > +		writeq_relaxed(smmu->evtq.q.q_base,
> > +			       smmu->base + ARM_SMMU_EVTQ_BASE);
> > +		writel_relaxed(smmu->evtq.q.llq.prod,
> > +			       smmu->page1 + ARM_SMMU_EVTQ_PROD);
> > +		writel_relaxed(smmu->evtq.q.llq.cons,
> > +			       smmu->page1 + ARM_SMMU_EVTQ_CONS);
> > +
> > +		enables |= CR0_EVTQEN;
> > +		ret = arm_smmu_write_reg_sync(smmu, enables, ARM_SMMU_CR0,
> > +					      ARM_SMMU_CR0ACK);
> 
> Nit:
> I believe only the write_reg_sync(CR0) should be under this if condition
> do we see any weird behavior if we perform the reg writes in
> kdump_kernel?

Since CR0_EVTQEN isn't set, the other three writes are dead code.

So, I skipped them.

Nicolin