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

[Leon Romanovsky <leon@kernel.org>]

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
> 
>