netdev - [PATCH net-next 04/15] mlxsw: pci: Arm CQ doorbell regardless of number of completions

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Date: Tue, 2 Apr 2024 15:54:17 +0200
From: Petr Machata <petrm@...dia.com>
To: "David S. Miller" <davem@...emloft.net>, Eric Dumazet
	<edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni
	<pabeni@...hat.com>, <netdev@...r.kernel.org>
CC: Ido Schimmel <idosch@...dia.com>, Amit Cohen <amcohen@...dia.com>, "Petr
 Machata" <petrm@...dia.com>, <mlxsw@...dia.com>
Subject: [PATCH net-next 04/15] mlxsw: pci: Arm CQ doorbell regardless of number of completions

From: Amit Cohen <amcohen@...dia.com>

Currently, as part of mlxsw_pci_cq_tasklet(), we check if any item
was handled, and only in such case we arm doorbell. This is unlikely case,
as we schedule tasklet only for CQs that we get an event for them, which
means that they contain completions to handle. Remove this check, which
is supposed to be true always, and even if it is false, it is not a mistake
to ring the doorbell. We can warn on such case, but it is not really worth
to add a check which will be run for each CQ handling when we do not expect
to reach it and it does not point to logic error that should be handled.

Signed-off-by: Amit Cohen <amcohen@...dia.com>
Reviewed-by: Ido Schimmel <idosch@...dia.com>
Signed-off-by: Petr Machata <petrm@...dia.com>
---
 drivers/net/ethernet/mellanox/mlxsw/pci.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/pci.c b/drivers/net/ethernet/mellanox/mlxsw/pci.c
index 2031487a9dae..3a5f902b625d 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/pci.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/pci.c
@@ -706,8 +706,8 @@ static void mlxsw_pci_cq_tasklet(struct tasklet_struct *t)
 		if (++items == credits)
 			break;
 	}
-	if (items)
-		mlxsw_pci_queue_doorbell_arm_consumer_ring(mlxsw_pci, q);
+
+	mlxsw_pci_queue_doorbell_arm_consumer_ring(mlxsw_pci, q);
 }

 static int mlxsw_pci_cq_init(struct mlxsw_pci *mlxsw_pci, char *mbox,
-- 
2.43.0