From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Wise Subject: [PATCH] RDMA/cxgb4: Don't exceed hw IQ depth limit for user CQs. Date: Wed, 01 Jun 2011 12:49:14 -0500 Message-ID: <20110601174913.18744.61491.stgit@build.ogc.int> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: roland-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org Memory allocated for user CQs gets rounded up to the next page boundary. And after rounding, we recalculate the resulting IQ depth and we need to make sure we don't exceed the HW limits. This bug can result a much smaller CQ allocated than was expected if the HW size field is exceeded, resulting in CQ overflow failures. Signed-off-by: Steve Wise --- drivers/infiniband/hw/cxgb4/cq.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/drivers/infiniband/hw/cxgb4/cq.c b/drivers/infiniband/hw/cxgb4/cq.c index 8d8f8ad..1720dc7 100644 --- a/drivers/infiniband/hw/cxgb4/cq.c +++ b/drivers/infiniband/hw/cxgb4/cq.c @@ -801,6 +801,10 @@ struct ib_cq *c4iw_create_cq(struct ib_device *ibdev, int entries, if (ucontext) { memsize = roundup(memsize, PAGE_SIZE); hwentries = memsize / sizeof *chp->cq.queue; + while (hwentries > T4_MAX_IQ_SIZE) { + memsize -= PAGE_SIZE; + hwentries = memsize / sizeof *chp->cq.queue; + } } chp->cq.size = hwentries; chp->cq.memsize = memsize; -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html