Re: [PATCH v1 04/16] ufs: core: mcq: Introduce Multi Circular Queue

[Asutosh Das]

On Mon, Sep 26 2022 at 07:50 -0700, Manivannan Sadhasivam wrote:
> On Thu, Sep 22, 2022 at 06:05:11PM -0700, Asutosh Das wrote:

[...]

> > diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
> > new file mode 100644
> > index 0000000..934556f
> > --- /dev/null
> > +++ b/drivers/ufs/core/ufs-mcq.c
[...]
> > +static int ufshcd_mcq_config_nr_queues(struct ufs_hba *hba)
> > +{
> > +	int i, rem;
> > +	u32 hbaq_cap, cmp, tot_queues;
> > +	struct Scsi_Host *host = hba->host;
> > +
> > +	hbaq_cap = hba->mcq_capabilities & 0xff;
>
> Define 0xff
>
> hbaq_cap should be named after the define used for 0xff. It is not quite
> understandable now.
Ok. I think you want the name hbaq_cap to be changed to what 0xff signifies.
Is that understanding correct?

> > +
> > +	if (!rw_queues)
> > +		rw_queues = num_possible_cpus();
> > +
> > +	tot_queues = dev_cmd_queue + read_queues + poll_queues + rw_queues;
> > +	if (hbaq_cap < tot_queues) {
> > +		dev_err(hba->dev, "Total queues (%d) exceeds HC capacity (%d)\n",
> > +			tot_queues, hbaq_cap);
> > +		return -EOPNOTSUPP;
> > +	}
> > +
> > +	rem = hbaq_cap - dev_cmd_queue;
> > +	cmp = rem;
> > +	hba->nr_queues[HCTX_TYPE_DEFAULT] = min3(cmp, rw_queues,
> > +						 num_possible_cpus());
> > +	rem -= hba->nr_queues[HCTX_TYPE_DEFAULT];
> > +	cmp = rem;
> > +	hba->nr_queues[HCTX_TYPE_POLL] = min(cmp, poll_queues);
>
> Hmm, so the driver is not using the number of queues set by the user?
> If the number varies, I don't think it should be configurable.
I think the driver would use the number of queues set by the user.
Because there's a check(hbaq_cap < tot_queues) above that ensures
that the HBA has enough queues for the given configuration.

-asd

>