DWRR (Deficit Weighted Round Robin) scheduling distributes bandwidth across traffic classes based on per-queue cost values, where lower cost means higher bandwidth share. The SPX5_DWRR_COST_MAX constant is 63 (6 bits) but the hardware register field HSCH_DWRR_ENTRY_DWRR_COST is GENMASK(24, 20), only 5 bits wide (max 31). This causes sparx5_weight_to_hw_cost() to compute cost values that silently overflow via FIELD_PREP, resulting in incorrect scheduling weights. Set SPX5_DWRR_COST_MAX to 31 to match the hardware register width. Fixes: 211225428d65 ("net: microchip: sparx5: add support for offloading ets qdisc") Signed-off-by: Daniel Machon --- drivers/net/ethernet/microchip/sparx5/sparx5_qos.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_qos.h b/drivers/net/ethernet/microchip/sparx5/sparx5_qos.h index 1231a80335d7..04f76f1e23f6 100644 --- a/drivers/net/ethernet/microchip/sparx5/sparx5_qos.h +++ b/drivers/net/ethernet/microchip/sparx5/sparx5_qos.h @@ -35,7 +35,7 @@ #define SPX5_SE_BURST_UNIT 4096 /* Dwrr */ -#define SPX5_DWRR_COST_MAX 63 +#define SPX5_DWRR_COST_MAX 31 struct sparx5_shaper { u32 mode; --- base-commit: 9384a1d1897a809f073a0f8cc252b7a41f9c05ac change-id: 20260210-sparx5-fix-dwrr-cost-max-f86d986fdc50 Best regards, -- Daniel Machon