Re: [RFC PATCH v3 2/4] ufs: core: mcq: Adds Multi-Circular Queue support

[Asutosh Das (asd)]

Hello Bean
Thanks for your comments. Responses inline.

On 9/5/2022 9:27 AM, Bean Huo wrote:
> On Fri, 2022-09-02 at 15:41 -0700, Asutosh Das wrote:
> > +
> > +static void ufshcd_mcq_config_nr_queues(struct ufs_hba *hba)
> > +{
> > +       int i, rem;
> > +       u32 hbaq_cap, cmp;
> > +       struct Scsi_Host *host = hba->host;
> > +
> > +       hbaq_cap = hba->mcq_capabilities & 0xff;
> > +
> > +       rem = hbaq_cap - dev_cmd_queue;
> > +       /* min() compares variables of same type */
> > +       hba->nr_queues[HCTX_TYPE_DEFAULT] = min(hbaq_cap -
> > dev_cmd_queue,
>
>   hba->nr_queues[HCTX_TYPE_DEFAULT] = min(rem, num_possible_cpus());
min() compares variables of same type only.
> > +                                               num_possible_cpus());
> > +       rem -= hba->nr_queues[HCTX_TYPE_DEFAULT];
> > +       if (rem <= 0)
> > +               goto out;
> > +       cmp = rem;
> > +       hba->nr_queues[HCTX_TYPE_POLL] = min(cmp, poll_queues);
> > +       rem -= hba->nr_queues[HCTX_TYPE_POLL];
> > +       if (rem <= 0)
> > +               goto out;
> > +       cmp = rem;
> > +       hba->nr_queues[HCTX_TYPE_READ] = min(cmp, read_queues);
>
> static read_queues is not initialized.
It would be initialized to 0. But I think we should configure it as a 
module parameter which is missing. Let me add it in the next version.
> >
> .....
> > +static inline void ufshcd_inc_tp(struct ufs_hw_queue *q)
> > +{
> > +       u32 mask = q->max_entries - 1;
> > +       u32 val;
> > +
> > +       q->sq_tp_slot = (q->sq_tp_slot + 1) & mask;
> > +       val = q->sq_tp_slot * sizeof(struct utp_transfer_req_desc);
> > +       writel(val, q->mcq_sq_tp);
> > +}
>
> This function just accesses the submission queue tail pointer. The
> function name should clearly explain this.
The reason for this naming was that only SQ's tail pointer can be 
updated by SW. I can add a _sq_ to this function in the next version. 
Plmk if you prefer a better name.

>