[PATCH v2 2/5] iommu/arm-smmu: Convert to a global static identity domain

[Jason Gunthorpe]

On Tue, Dec 12, 2023 at 01:27:08PM +0000, Will Deacon wrote:
> > +static int arm_smmu_attach_dev_identity(struct iommu_domain *domain,
> > +					struct device *dev)
> > +{
> > +	struct arm_smmu_master_cfg *cfg = dev_iommu_priv_get(dev);
> > +	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
> > +	struct arm_smmu_device *smmu;
> > +	int ret;
> > +
> > +	if (!cfg)
> > +		return -ENODEV;
> > +	smmu = cfg->smmu;
> > +
> > +	ret = arm_smmu_rpm_get(smmu);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	arm_smmu_master_install_s2crs(cfg, S2CR_TYPE_BYPASS, 0, fwspec);
> > +
> > +	pm_runtime_set_autosuspend_delay(smmu->dev, 20);
> > +	pm_runtime_use_autosuspend(smmu->dev);
> 
> This is cargo-culted from arm_smmu_attach_dev() with the comments dropped
> and it's not clear at all to me that the autosuspend delay makes any sense
> for the identity domain.

Indeed, however it was how it worked before this split up.

> So I think it would be better to either drop the call to
> pm_runtime_set_autosuspend_delay() 

I looked through it more carefully and this does seem like the right
thing, so I will drop them.

Thanks,
Jason