> On Thu, Aug 10, 2017 at 02:15:57PM +0300, Leon Romanovsky wrote:
> > On Thu, Aug 10, 2017 at 12:46:15AM -0700, Adit Ranadive wrote:
> > > From: Bryan Tan <bryantan@xxxxxxxxxx>
> > >
> > > There is a chance of a race between arming the CQ and receiving
> > > completions. By reporting CQ missed events any ULPs should poll
> > > again to get the completions.
> > >
> > > Fixes: 29c8d9eba550 ("IB: Add vmw_pvrdma driver")
> > > Acked-by: Aditya Sarwade <asarwade@xxxxxxxxxx>
> > > Signed-off-by: Bryan Tan <bryantan@xxxxxxxxxx>
> > > Signed-off-by: Adit Ranadive <aditr@xxxxxxxxxx>
> > > ---
> > > drivers/infiniband/hw/vmw_pvrdma/pvrdma_cq.c | 15 +++++++++++++++
> > > 1 file changed, 15 insertions(+)
> > >
> > > diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_cq.c b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_cq.c
> > > index 69bda61..f4ab5fa 100644
> > > --- a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_cq.c
> > > +++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_cq.c
> > > @@ -65,12 +65,27 @@ int pvrdma_req_notify_cq(struct ib_cq *ibcq,
> > > struct pvrdma_dev *dev = to_vdev(ibcq->device);
> > > struct pvrdma_cq *cq = to_vcq(ibcq);
> > > u32 val = cq->cq_handle;
> > > + unsigned long flags;
> > >
> > > val |= (notify_flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED ?
> > > PVRDMA_UAR_CQ_ARM_SOL : PVRDMA_UAR_CQ_ARM;
> > >
> > > + spin_lock_irqsave(&cq->cq_lock, flags);
> > > +
> > > pvrdma_write_uar_cq(dev, val);
> > >
> > > + if (notify_flags & IB_CQ_REPORT_MISSED_EVENTS) {
> > > + unsigned int head;
> > > +
> > > + if (pvrdma_idx_ring_has_data(&cq->ring_state->rx,
> > > + cq->ibcq.cqe, &head)) {
> >
> > The pvrdma_idx_ring_has_data function can return PVRDMA_INVALID_IDX (-1).
>
> I believe that the case of PVRDMA_INVALID_IDX is only due to some bug. I do
> not think it is an expected behaviour, it means that ring is corrupted, am
> i right Adit?
Thanks Leon, Yuval. While hitting the INVALID_IDX is really rare (we haven't hit it ever in our internal testing), we should check this for consistency purposes. Look for a v1.
- Adit--
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