This is a note to let you know that I've just added the patch titled
ntb_transport: fix qp count bug
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ntb_transport-fix-qp-count-bug.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cb827ee6ccc3e480f0d9c0e8e53eef55be5b0414 Mon Sep 17 00:00:00 2001
From: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Date: Mon, 5 Jun 2017 14:00:52 -0600
Subject: ntb_transport: fix qp count bug
From: Logan Gunthorpe <logang@xxxxxxxxxxxx>
commit cb827ee6ccc3e480f0d9c0e8e53eef55be5b0414 upstream.
In cases where there are more mw's than spads/2-2, the mw count gets
reduced to match the limitation. ntb_transport also tries to ensure that
there are fewer qps than mws but uses the full mw count instead of
the reduced one. When this happens, the math in
'ntb_transport_setup_qp_mw' will get confused and result in a kernel
paging request bug.
This patch fixes the bug by reducing qp_count to the reduced mw count
instead of the full mw count.
Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Fixes: e26a5843f7f5 ("NTB: Split ntb_hw_intel and ntb_transport drivers")
Acked-by: Allen Hubbe <Allen.Hubbe@xxxxxxxx>
Signed-off-by: Jon Mason <jdmason@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/ntb/ntb_transport.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -1125,8 +1125,8 @@ static int ntb_transport_probe(struct nt
qp_count = ilog2(qp_bitmap);
if (max_num_clients && max_num_clients < qp_count)
qp_count = max_num_clients;
- else if (mw_count < qp_count)
- qp_count = mw_count;
+ else if (nt->mw_count < qp_count)
+ qp_count = nt->mw_count;
qp_bitmap &= BIT_ULL(qp_count) - 1;
Patches currently in stable-queue which might be from logang@xxxxxxxxxxxx are
queue-4.9/ntb-ntb_test-fix-bug-printing-ntb_perf-results.patch
queue-4.9/ntb_transport-fix-bug-calculating-num_qps_mw.patch
queue-4.9/ntb-ntb_test-ensure-the-link-is-up-before-trying-to-configure-the-mws.patch
queue-4.9/ntb_transport-fix-qp-count-bug.patch