[PATCH 4.9 059/177] qed: Fix interrupt flags on Rx LL2

From: Greg Kroah-Hartman
Date: Mon Dec 18 2017 - 12:30:43 EST

4.9-stable review patch. If anyone has any objections, please let me know.


From: Ram Amrani <Ram.Amrani@xxxxxxxxxx>

[ Upstream commit 1df2adedcce17ad4a39fba74f0e2b611f797fe10 ]

Before iterating over the the LL2 Rx ring, the ring's
spinlock is taken via spin_lock_irqsave().
The actual processing of the packet [including handling
by the protocol driver] is done without said lock,
so qed releases the spinlock and re-claims it afterwards.

Problem is that the final spin_lock_irqrestore() at the end
of the iteration uses the original flags saved from the
initial irqsave() instead of the flags from the most recent
irqsave(). So it's possible that the interrupt status would
be incorrect at the end of the processing.

Fixes: 0a7fb11c23c0 ("qed: Add Light L2 support");
CC: Ram Amrani <Ram.Amrani@xxxxxxxxxx>
Signed-off-by: Yuval Mintz <Yuval.Mintz@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
drivers/net/ethernet/qlogic/qed/qed_ll2.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/net/ethernet/qlogic/qed/qed_ll2.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_ll2.c
@@ -443,7 +443,7 @@ qed_ll2_rxq_completion_gsi(struct qed_hw
static int qed_ll2_rxq_completion_reg(struct qed_hwfn *p_hwfn,
struct qed_ll2_info *p_ll2_conn,
union core_rx_cqe_union *p_cqe,
- unsigned long lock_flags,
+ unsigned long *p_lock_flags,
bool b_last_cqe)
struct qed_ll2_rx_queue *p_rx = &p_ll2_conn->rx_queue;
@@ -464,10 +464,10 @@ static int qed_ll2_rxq_completion_reg(st
"Mismatch between active_descq and the LL2 Rx chain\n");
list_add_tail(&p_pkt->list_entry, &p_rx->free_descq);

- spin_unlock_irqrestore(&p_rx->lock, lock_flags);
+ spin_unlock_irqrestore(&p_rx->lock, *p_lock_flags);
qed_ll2b_complete_rx_packet(p_hwfn, p_ll2_conn->my_id,
p_pkt, &p_cqe->rx_cqe_fp, b_last_cqe);
- spin_lock_irqsave(&p_rx->lock, lock_flags);
+ spin_lock_irqsave(&p_rx->lock, *p_lock_flags);

return 0;
@@ -507,7 +507,8 @@ static int qed_ll2_rxq_completion(struct
rc = qed_ll2_rxq_completion_reg(p_hwfn, p_ll2_conn,
- cqe, flags, b_last_cqe);
+ cqe, &flags,
+ b_last_cqe);
rc = -EIO;