| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 087/453] RDMA/rxe: Compute PSN windows correctly | Date | Mon, 28 Dec 2020 13:45:23 +0100 |
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From: Bob Pearson <rpearsonhpe@gmail.com>
[ Upstream commit bb3ab2979fd69db23328691cb10067861df89037 ]
The code which limited the number of unacknowledged PSNs was incorrect. The PSNs are limited to 24 bits and wrap back to zero from 0x00ffffff. The test was computing a 32 bit value which wraps at 32 bits so that qp->req.psn can appear smaller than the limit when it is actually larger.
Replace '>' test with psn_compare which is used for other PSN comparisons and correctly handles the 24 bit size.
Fixes: 8700e3e7c485 ("Soft RoCE driver") Link: https://lore.kernel.org/r/20201013170741.3590-1-rpearson@hpe.com Signed-off-by: Bob Pearson <rpearson@hpe.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/infiniband/sw/rxe/rxe_req.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_req.c b/drivers/infiniband/sw/rxe/rxe_req.c index e5031172c0193..a4d6e0b7901e9 100644 --- a/drivers/infiniband/sw/rxe/rxe_req.c +++ b/drivers/infiniband/sw/rxe/rxe_req.c @@ -664,7 +664,8 @@ next_wqe: } if (unlikely(qp_type(qp) == IB_QPT_RC && - qp->req.psn > (qp->comp.psn + RXE_MAX_UNACKED_PSNS))) { + psn_compare(qp->req.psn, (qp->comp.psn + + RXE_MAX_UNACKED_PSNS)) > 0)) { qp->req.wait_psn = 1; goto exit; } -- 2.27.0
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