Re: [PATCH 13/25] scsi: hisi_sas: add path from phyup irq to SAS framework

[John Garry]

On 16/10/2015 13:55, Arnd Bergmann wrote:
> On Monday 12 October 2015 23:20:25 John Garry wrote:
> > @@ -804,6 +818,16 @@ static irqreturn_t int_phyup_v1_hw(int irq_no, void *p)
> >                  phy->identify.target_port_protocols =
> >                          SAS_PROTOCOL_SMP;
> >
> > +       wq = kmalloc(sizeof(*wq), GFP_ATOMIC);
> > +       if (!wq)
> > +               goto end;
> > +
> > +       wq->event = PHYUP;
> > +       wq->hisi_hba = hisi_hba;
> > +       wq->phy_no = phy_no;
> > +
> > +       INIT_WORK(&wq->work_struct, hisi_sas_wq_process);
> > +       queue_work(hisi_hba->wq, &wq->work_struct);
> >
> >   end:
> >          hisi_sas_phy_write32(hisi_hba, phy_no, CHL_INT2,
>
> While rereading some other parts of the code, I stumbled over this piece.
> You should generally not allocate work structs dynamically. Why not embed
> the work struct inside of the phy structure and then just queue that?
>
> 	Arnd
>
> .

It could be considered.

A potential issue I see is with hisi_sas_control_phy() for 
PHY_FUNC_HARD_RESET: this allocates a hisi_sas_wq struct and processes 
the reset in the queue work. When we re-enable the phy for the reset, 
the phyup irq will want to use the same hisi_sas_wq struct which may be 
in use.

hisi_sas_control_phy() is added in 23/35.

John

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