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authorLogan Gunthorpe <logang@deltatee.com>2017-06-05 14:00:53 -0600
committerJon Mason <jdmason@kudzu.us>2017-06-19 14:24:41 -0400
commit8e8496e0e9564b66165f5219a4e8ed20b0d3fc6b (patch)
tree13e3ec29ae0b69a45fca5021525024b2b7c5da9b /drivers
parentcb827ee6ccc3e480f0d9c0e8e53eef55be5b0414 (diff)
downloadlinux-stericsson-8e8496e0e9564b66165f5219a4e8ed20b0d3fc6b.tar.gz
ntb_transport: fix bug calculating num_qps_mw
A divide by zero error occurs if qp_count is less than mw_count because num_qps_mw is calculated to be zero. The calculation appears to be incorrect. The requirement is for num_qps_mw to be set to qp_count / mw_count with any remainder divided among the earlier mws. For example, if mw_count is 5 and qp_count is 12 then mws 0 and 1 will have 3 qps per window and mws 2 through 4 will have 2 qps per window. Thus, when mw_num < qp_count % mw_count, num_qps_mw is 1 higher than when mw_num >= qp_count. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Fixes: e26a5843f7f5 ("NTB: Split ntb_hw_intel and ntb_transport drivers") Acked-by: Allen Hubbe <Allen.Hubbe@dell.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/ntb/ntb_transport.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 0a778d2cab94..5b6b00ea6ed9 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -623,7 +623,7 @@ static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
if (!mw->virt_addr)
return -ENOMEM;
- if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
+ if (mw_num < qp_count % mw_count)
num_qps_mw = qp_count / mw_count + 1;
else
num_qps_mw = qp_count / mw_count;
@@ -1000,7 +1000,7 @@ static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
qp->event_handler = NULL;
ntb_qp_link_down_reset(qp);
- if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
+ if (mw_num < qp_count % mw_count)
num_qps_mw = qp_count / mw_count + 1;
else
num_qps_mw = qp_count / mw_count;