From 67fa8bfff771973a6867ca4be8b6c29e6e2e312f Mon Sep 17 00:00:00 2001 From: Logan Gunthorpe Date: Mon, 18 Dec 2017 11:25:05 -0700 Subject: [PATCH] ntb_transport: Fix bug with max_mw_size parameter [ Upstream commit cbd27448faff4843ac4b66cc71445a10623ff48d ] 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 Acked-by: Allen Hubbe Cc: Dave Jiang Signed-off-by: Jon Mason Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- 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 f58d8e305323..18339b7e88a4 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -998,6 +998,9 @@ 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); -- 2.20.1