Subject: Re: [PATCH 3/5] iommu/arm-smmu-v3: Add Stream Table Entry display to debugfs

From: Nicolin Chen <[email-masked]>
Date: Tue, 26 May 2026 19:43:06 -0700

On Tue, May 26, 2026 at 07:18:54PM -0700, Nicolin Chen wrote:
> On Wed, May 20, 2026 at 02:37:09PM +0800, Qinxin Xia wrote:
> > +int arm_smmu_debugfs_create_stream_table(struct arm_smmu_device *smmu,
> > +					 struct device *dev)
> > +{
> > +	struct dentry *stream_dir, *dev_dir;
> > +	struct arm_smmu_master *master;
> > +	struct ste_context *ctx;
> > +	char name[64];
> > +	u32 sid;
> > +	int i;
> [...]
> > +	master = dev_iommu_priv_get(dev);
> > +	if (!master || !master->num_streams)
> > +		return -ENODEV;
> 
> The caller has master. Why not just pass it in? Then, you would
> have master->smmu and master->dev.

I forgot that this is to fence against concurrent device unplug.

Maybe add a note for the reason of having smmu and dev instead?

Nicolin