mlxsw: __mlxsw_sp_port_headroom_set(): Fix a use of local variable

[ Upstream commit 289460404f6947ef1c38e67d680be9a84161250b ]

The function-local variable "delay" enters the loop interpreted as delay
in bits. However, inside the loop it gets overwritten by the result of
mlxsw_sp_pg_buf_delay_get(), and thus leaves the loop as quantity in
cells. Thus on second and further loop iterations, the headroom for a
given priority is configured with a wrong size.

Fix by introducing a loop-local variable, delay_cells. Rename thres to
thres_cells for consistency.

Fixes: f417f04da589 ("mlxsw: spectrum: Refactor port buffer configuration")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index d64cd8d..a12b571 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -841,8 +841,9 @@ int __mlxsw_sp_port_headroom_set(struct mlxsw_sp_port *mlxsw_sp_port, int mtu,
        for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++) {
                bool configure = false;
                bool pfc = false;
+               u16 thres_cells;
+               u16 delay_cells;
                bool lossy;
-               u16 thres;
 
                for (j = 0; j < IEEE_8021QAZ_MAX_TCS; j++) {
                        if (prio_tc[j] == i) {
@@ -856,10 +857,11 @@ int __mlxsw_sp_port_headroom_set(struct mlxsw_sp_port *mlxsw_sp_port, int mtu,
                        continue;
 
                lossy = !(pfc || pause_en);
-               thres = mlxsw_sp_pg_buf_threshold_get(mlxsw_sp, mtu);
-               delay = mlxsw_sp_pg_buf_delay_get(mlxsw_sp, mtu, delay, pfc,
-                                                 pause_en);
-               mlxsw_sp_pg_buf_pack(pbmc_pl, i, thres + delay, thres, lossy);
+               thres_cells = mlxsw_sp_pg_buf_threshold_get(mlxsw_sp, mtu);
+               delay_cells = mlxsw_sp_pg_buf_delay_get(mlxsw_sp, mtu, delay,
+                                                       pfc, pause_en);
+               mlxsw_sp_pg_buf_pack(pbmc_pl, i, thres_cells + delay_cells,
+                                    thres_cells, lossy);
        }
 
        return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(pbmc), pbmc_pl);