4.20-stable review patch. If anyone has any objections, please let me know.
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[ 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 --- 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);