mlx4_core: fix wrong comment about the reason of subtract one from the max_cqes

Signed-off-by: Dotan Barak <[email protected]>
Signed-off-by: Eli Cohen <[email protected]>
Signed-off-by: Vladimir Sokolovsky <[email protected]>
(Ported from Mellanox OFED 2.4)

Signed-off-by: Mukesh Kacker <[email protected]>

Orabug: 27510504

(cherry picked from commit 03857fc)
cherry-pick-repo=linux-uek.git

Signed-off-by: Qing Huang <[email protected]>
Signed-off-by: Aron Silverton <[email protected]>
Signed-off-by: Somasundaram Krishnasamy <[email protected]>

Author: Dotan Barak

drivers/net/ethernet/mellanox/mlx4/main.c

@@ -471,8 +471,7 @@ static int mlx4_dev_cap(struct mlx4_dev *dev, struct mlx4_dev_cap *dev_cap)
 	dev->caps.max_rq_desc_sz     = dev_cap->max_rq_desc_sz;
 	/*
 	 * Subtract 1 from the limit because we need to allocate a
-	 * spare CQE so the HCA HW can tell the difference between an
-	 * empty CQ and a full CQ.
+	 * spare CQE to enable resizing the CQ
 	 */
 	dev->caps.max_cqes	     = dev_cap->max_cq_sz - 1;
 	dev->caps.reserved_cqs	     = dev_cap->reserved_cqs;