From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ale.deltatee.com (ale.deltatee.com. [207.54.116.67]) by gmr-mx.google.com with ESMTPS id k67si609975vki.0.2017.12.08.16.02.25 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 08 Dec 2017 16:02:25 -0800 (PST) From: Logan Gunthorpe Date: Fri, 8 Dec 2017 17:02:16 -0700 Message-Id: <20171209000217.18366-1-logang@deltatee.com> Subject: [PATCH 1/2] ntb_transport: Fix bug with max_mw_size parameter To: linux-ntb@googlegroups.com, linux-kernel@vger.kernel.org Cc: Logan Gunthorpe , Jon Mason , Dave Jiang , Allen Hubbe List-ID: When using the max_mw_size parameter of ntb_transport to limit the size of the Memory windows, communication cannot be established and the queues freeze. This is because the mw_size that's reported to the peer is correctly limited but the size used locally is not. So the MW is initialized with a buffer smaller than the window but the TX side is using the full window. This means the TX side will be writing to a region of the window that points nowhere. This is easily fixed by applying the same limit to tx_size in ntb_transport_init_queue(). Fixes: e26a5843f7f5 ("NTB: Split ntb_hw_intel and ntb_transport drivers") Signed-off-by: Logan Gunthorpe Cc: Jon Mason Cc: Dave Jiang Cc: Allen Hubbe --- drivers/ntb/ntb_transport.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index 045e3dd4750e..9878c48826e3 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -1003,6 +1003,9 @@ static int ntb_transport_init_queue(struct ntb_transport_ctx *nt, mw_base = nt->mw_vec[mw_num].phys_addr; mw_size = nt->mw_vec[mw_num].phys_size; + if (max_mw_size && mw_size > max_mw_size) + mw_size = max_mw_size; + tx_size = (unsigned int)mw_size / num_qps_mw; qp_offset = tx_size * (qp_num / mw_count); -- 2.11.0