Re: [PATCH v11 4/4] stmmac: s32: enable support for Multi-IRQ mode

Jared Kangas
2026-04-21T20:03:06Z

Hi Jan,

On Thu, Mar 12, 2026 at 09:55:30AM +0100, Jan Petrous via B4 Relay wrote:
> From: "Jan Petrous (OSS)" <jan.petrous@oss.nxp.com>
>
> Based on previous changes in platform driver, the vendor
> glue driver can enable Multi-IRQ mode, if needed.
>
> [...]
>
> If those prerequisites are met, the driver switches to Multi-IRQ mode,
> using per-queue IRQs for rx/tx data pathr:
>
> [ 1.387045] s32-dwmac 4033c000.ethernet: Multi-IRQ mode (per queue IRQs) selected
>
> Now the driver owns all queues IRQs:
>
> root@s32g399aevb3:~# grep eth /proc/interrupts
> 29: 0 0 0 0 0 0 0 0 GICv3 89 Level eth0:mac
> 30: 0 0 0 0 0 0 0 0 GICv3 91 Level eth0:rx-0
> 31: 0 0 0 0 0 0 0 0 GICv3 93 Level eth0:rx-1
> 32: 0 0 0 0 0 0 0 0 GICv3 95 Level eth0:rx-2
> 33: 0 0 0 0 0 0 0 0 GICv3 97 Level eth0:rx-3
> 34: 0 0 0 0 0 0 0 0 GICv3 99 Level eth0:rx-4
> 35: 0 0 0 0 0 0 0 0 GICv3 90 Level eth0:tx-0
> 36: 0 0 0 0 0 0 0 0 GICv3 92 Level eth0:tx-1
> 37: 0 0 0 0 0 0 0 0 GICv3 94 Level eth0:tx-2
> 38: 0 0 0 0 0 0 0 0 GICv3 96 Level eth0:tx-3
> 39: 0 0 0 0 0 0 0 0 GICv3 98 Level eth0:tx-4

I ran this series' changes on an NXP S32G-VNP-RDB3 (dwmac-s32) and
confirmed multichannel TX by doing a basic iperf3 throughput test:

# dmesg | grep Multi-IRQ
[ 37.463467] s32-dwmac 4033c000.ethernet: Multi-IRQ mode (per queue IRQs) selected
# iperf3 -s
[connection logs snipped]
# grep end0 /proc/interrupts | column -t
29: 0 0 0 0 0 0 0 0 GICv3 89 Level end0:mac
30: 968 0 0 0 0 0 0 0 GICv3 90 Level end0:tx-0
31: 0 3 0 0 0 0 0 0 GICv3 92 Level end0:tx-1
32: 0 0 3 0 0 0 0 0 GICv3 94 Level end0:tx-2
33: 0 0 0 3 0 0 0 0 GICv3 96 Level end0:tx-3
34: 0 0 0 0 3 0 0 0 GICv3 98 Level end0:tx-4
35: 67302 0 0 0 0 0 0 0 GICv3 91 Level end0:rx-0
36: 0 0 0 0 0 0 0 0 GICv3 93 Level end0:rx-1
37: 0 0 0 0 0 0 0 0 GICv3 95 Level end0:rx-2
38: 0 0 0 0 0 0 0 0 GICv3 97 Level end0:rx-3
39: 0 0 0 0 0 0 0 0 GICv3 99 Level end0:rx-4

Also tried out multichannel RX by adding 'snps,route-multi-broad' to
rx-queues-config/queue2 in the devicetree, which showed activity on
the corresponding rx-2 entry:

# grep end0 /proc/interrupts | column -t
29: 0 0 0 0 0 0 0 0 GICv3 89 Level end0:mac
30: 4 0 0 0 0 0 0 0 GICv3 90 Level end0:tx-0
31: 0 1 0 0 0 0 0 0 GICv3 92 Level end0:tx-1
32: 0 0 1 0 0 0 0 0 GICv3 94 Level end0:tx-2
33: 0 0 0 0 0 0 0 0 GICv3 96 Level end0:tx-3
34: 0 0 0 0 1 0 0 0 GICv3 98 Level end0:tx-4
35: 68 0 0 0 0 0 0 0 GICv3 91 Level end0:rx-0
36: 0 0 0 0 0 0 0 0 GICv3 93 Level end0:rx-1
37: 0 0 91 0 0 0 0 0 GICv3 95 Level end0:rx-2
38: 0 0 0 0 0 0 0 0 GICv3 97 Level end0:rx-3
39: 0 0 0 0 0 0 0 0 GICv3 99 Level end0:rx-4

I didn't see any regressions with light network usage, and both TX/RX
appear to function as expected.

Tested-by: Jared Kangas <jkangas@redhat.com>