[PATCH net v2] Revert "qed: fix possible unpaired spin_{un}lock_bh in _qed_mcp_cmd_and_union()"

From: Jia He
Date: Tue Jul 20 2021 - 09:34:04 EST


This reverts commit 6206b7981a36476f4695d661ae139f7db36a802d.

That patch added additional spin_{un}lock_bh(), which was harmless
but pointless. The orginal code path has guaranteed the pair of
spin_{un}lock_bh().

We'd better revert it before we find the exact root cause of the
bug_on mentioned in that patch.

Fixes: 6206b7981a36 ("qed: fix possible unpaired spin_{un}lock_bh in _qed_mcp_cmd_and_union()")
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Prabhakar Kushwaha <pkushwaha@xxxxxxxxxxx>
Signed-off-by: Jia He <justin.he@xxxxxxx>

---
v2: correct the hash value of reverted commit, and add the fixes tag

drivers/net/ethernet/qlogic/qed/qed_mcp.c | 23 ++++++-----------------
1 file changed, 6 insertions(+), 17 deletions(-)

diff --git a/drivers/net/ethernet/qlogic/qed/qed_mcp.c b/drivers/net/ethernet/qlogic/qed/qed_mcp.c
index 79d879a5d663..4387292c37e2 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_mcp.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_mcp.c
@@ -474,18 +474,14 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,

spin_lock_bh(&p_hwfn->mcp_info->cmd_lock);

- if (!qed_mcp_has_pending_cmd(p_hwfn)) {
- spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);
+ if (!qed_mcp_has_pending_cmd(p_hwfn))
break;
- }

rc = qed_mcp_update_pending_cmd(p_hwfn, p_ptt);
- if (!rc) {
- spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);
+ if (!rc)
break;
- } else if (rc != -EAGAIN) {
+ else if (rc != -EAGAIN)
goto err;
- }

spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);

@@ -502,8 +498,6 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,
return -EAGAIN;
}

- spin_lock_bh(&p_hwfn->mcp_info->cmd_lock);
-
/* Send the mailbox command */
qed_mcp_reread_offsets(p_hwfn, p_ptt);
seq_num = ++p_hwfn->mcp_info->drv_mb_seq;
@@ -530,18 +524,14 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,

spin_lock_bh(&p_hwfn->mcp_info->cmd_lock);

- if (p_cmd_elem->b_is_completed) {
- spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);
+ if (p_cmd_elem->b_is_completed)
break;
- }

rc = qed_mcp_update_pending_cmd(p_hwfn, p_ptt);
- if (!rc) {
- spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);
+ if (!rc)
break;
- } else if (rc != -EAGAIN) {
+ else if (rc != -EAGAIN)
goto err;
- }

spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);
} while (++cnt < max_retries);
@@ -564,7 +554,6 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,
return -EAGAIN;
}

- spin_lock_bh(&p_hwfn->mcp_info->cmd_lock);
qed_mcp_cmd_del_elem(p_hwfn, p_cmd_elem);
spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);

--
2.17.1