4.20-stable review patch. If anyone has any objections, please let me know.
------------------
[ 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 <pe...@mellanox.com>
Acked-by: Jiri Pirko <j...@mellanox.com>
Signed-off-by: Ido Schimmel <ido...@mellanox.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
drivers/net/ethernet/mellanox/mlxsw/spectrum.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 8f1180fff9551..280173b489624 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -845,8 +845,9 @@ 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) {
@@ -860,10 +861,11 @@ 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);
--
2.19.1
