Re: [PATCH for-rc v2] RDMA/cxgb4: notify rdma stack for IB_EVENT_QP_LAST_WQE_REACHED event

[Anumula Murali Mohan Reddy <anumula@chelsio.com>]

On Tuesday, January 01/07/25, 2025 at 15:49:11 +0530, Leon Romanovsky wrote:
> On Tue, Jan 07, 2025 at 03:20:53PM +0530, Anumula Murali Mohan Reddy wrote:
> > This patch sends IB_EVENT_QP_LAST_WQE_REACHED event on a QP that is in
> > error state and associated with an SRQ. This behaviour is incorporated
> > in flush_qp() which is called when QP transitions to error state.
> > Supports SRQ drain functionality added by commit 844bc12e6da3 ("IB/core:
> > add support for draining Shared receive queues")
> > 
> > Fixes: 844bc12e6da3 ("IB/core: add support for draining Shared receive queues")
> > Signed-off-by: Anumula Murali Mohan Reddy <anumula@chelsio.com>
> > Signed-off-by: Potnuri Bharat Teja <bharat@chelsio.com>
> > ---
> > Changes since v1:
> > Addressed previous review comments
> 
> There are two review comments. One is Fixes line, which is not a big deal
> as I can add it when applying patch, but what about second comment?
> 
> Why is this event limited to QP with SRQ only?
> https://lore.kernel.org/all/20250105090622.GA5511@unreal/
> 
> Thanks
> 
> > ---
> >  drivers/infiniband/hw/cxgb4/qp.c | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> > 
> > diff --git a/drivers/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c
> > index 7b5c4522b426..10f61bc16dd5 100644
> > --- a/drivers/infiniband/hw/cxgb4/qp.c
> > +++ b/drivers/infiniband/hw/cxgb4/qp.c
> > @@ -1599,6 +1599,7 @@ static void __flush_qp(struct c4iw_qp *qhp, struct c4iw_cq *rchp,
> >  	int count;
> >  	int rq_flushed = 0, sq_flushed;
> >  	unsigned long flag;
> > +	struct ib_event ev;
> >  
> >  	pr_debug("qhp %p rchp %p schp %p\n", qhp, rchp, schp);
> >  
> > @@ -1607,6 +1608,14 @@ static void __flush_qp(struct c4iw_qp *qhp, struct c4iw_cq *rchp,
> >  	if (schp != rchp)
> >  		spin_lock(&schp->lock);
> >  	spin_lock(&qhp->lock);
> > +	if (qhp->srq) {
> > +		if (qhp->attr.state == C4IW_QP_STATE_ERROR && qhp->ibqp.event_handler) {
> > +			ev.device = qhp->ibqp.device;
> > +			ev.element.qp = &qhp->ibqp;
> > +			ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
> > +			qhp->ibqp.event_handler(&ev, qhp->ibqp.qp_context);
> > +		}
> > +	}
> >  
> >  	if (qhp->wq.flushed) {
> >  		spin_unlock(&qhp->lock);
> > -- 
> > 2.39.3
> > 
> >
RDMA stack expects the IB_EVENT_QP_LAST_WQE_REACHED event only for SRQ
, for non-SRQ  it is handled via the drain cqe

Thanks,
Anumula Murali Mohan Reddy