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| author | Logan Gunthorpe <logang@deltatee.com> | 2017-06-05 22:00:53 +0200 |
|---|---|---|
| committer | Jon Mason <jdmason@kudzu.us> | 2017-06-19 20:24:41 +0200 |
| commit | 8e8496e0e9564b66165f5219a4e8ed20b0d3fc6b (patch) | |
| tree | 13e3ec29ae0b69a45fca5021525024b2b7c5da9b /drivers/ntb | |
| parent | ntb_transport: fix qp count bug (diff) | |
| download | linux-8e8496e0e9564b66165f5219a4e8ed20b0d3fc6b.tar.xz linux-8e8496e0e9564b66165f5219a4e8ed20b0d3fc6b.zip | |
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/ntb')
| -rw-r--r-- | drivers/ntb/ntb_transport.c | 4 |
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; |