Re: [PATCH v8 09/12] iommu/arm-smmu-v3: Implement pm_runtime & system sleep ops

[Pranjal Shrivastava <praan@google.com>]

On Tue, Jun 02, 2026 at 08:27:22AM -0700, Daniel Mentz wrote:
> On Mon, Jun 1, 2026 at 2:59 PM Pranjal Shrivastava <praan@google.com> wrote:
> > +static inline u32 arm_smmu_cmdq_owner_prod_idx(struct arm_smmu_cmdq *cmdq)
> > +{
> > +       return atomic_read(&cmdq->owner_prod) & CMDQ_PROD_IDX_MASK;
> 
> Is this masking necessary? Can't we just use
> atomic_read(&cmdq->owner_prod) as is? The only place in
> arm_smmu_cmdq_issue_cmdlist() that writes to cmdq->owner_prod already
> applied CMDQ_PROD_IDX_MASK.

Ack. I'll drop the masking.

> 
> > +}
> > +
> 
> > @@ -4839,6 +4876,10 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu)
> >                 return ret;
> >         }
> >
> > +       /* Clear any flags from the previous life */
> > +       atomic_andnot(CMDQ_PROD_STOP_FLAG, &smmu->cmdq.owner_prod);
> 
> Same. I believe CMDQ_PROD_STOP_FLAG will never be set in
> smmu->cmdq.owner_prod. Hence, clearing it shouldn't be necessary.

Ack. I'll drop this.

> 
> > +       atomic_andnot(CMDQ_PROD_STOP_FLAG, &smmu->cmdq.q.llq.atomic.prod);
> > +
> >         /* Invalidate any cached configuration */
> >         arm_smmu_cmdq_issue_cmd_with_sync(smmu, arm_smmu_make_cmd_cfgi_all());
> >
> > @@ -4898,6 +4939,21 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu)

Thanks,
Praan