Re: [PATCH net-next 1/3] net: bcmgenet: collapse TX priority queues to a single queue

[Justin Chen <justin.chen@broadcom.com>]

On 6/12/26 1:59 PM, Nicolai Buchwitz wrote:
> The strict-priority TX queues can starve under multi-queue load and
> trip NETDEV_WATCHDOG. Justin's earlier series [1] worked around the
> symptom but kept the design.
> 
> The multi-queue design was originally used for STB use cases that are
> no longer needed, as confirmed by Justin. v1 hw_params already
> exercises a single-queue path. Point v2-v4 at the same configuration:
> ring 0 takes the full BD pool, every per-ring loop collapses to one
> iteration, and netif_set_real_num_tx_queues drops to 1 via the
> existing tx_queues + 1 arithmetic.
> 
> Tested on Raspberry Pi CM4 (BCM2711). The baseline kernel trips
> NETDEV_WATCHDOG within seconds under iperf3 UDP saturation
> (-u -b0 -P16 -t60). After the change the same test completes
> without a watchdog, and a single-stream 60 s UDP run sustains
> 956 Mbit/s with 0/4952890 datagrams lost. Single-stream TCP
> throughput is unchanged at 943 Mbit/s.
> 
> [1] https://lore.kernel.org/netdev/20260406175756.134567-1-justin.chen@broadcom.com/
> 
> Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de>

Reviewed-by: Justin Chen <justin.chen@broadcom.com>
Tested-by: Justin Chen <justin.chen@broadcom.com>