Re: [PATCH net-next v9 0/3] Add minimal XDP support to TI AM65 CPSW Ethernet driver

[Julien Panis <jpanis@baylibre.com>]

On 4/18/24 13:25, Siddharth Vadapalli wrote:
> On Thu, Apr 18, 2024 at 01:17:47PM +0200, Julien Panis wrote:
>> On 4/18/24 13:00, Siddharth Vadapalli wrote:
>>> On 12-04-2024 21:08, Julien Panis wrote:
>>>> This patch adds XDP support to TI AM65 CPSW Ethernet driver.
>>>>
>>>> The following features are implemented: NETDEV_XDP_ACT_BASIC,
>>>> NETDEV_XDP_ACT_REDIRECT, and NETDEV_XDP_ACT_NDO_XMIT.
>>>>
>>>> Zero-copy and non-linear XDP buffer supports are NOT implemented.
>>>>
>>>> Besides, the page pool memory model is used to get better performance.
>>>>
>>>> Signed-off-by: Julien Panis <jpanis@baylibre.com>
>>> Hello Julien,
>>>
>>> This series crashes Linux on AM62ax SoC which also uses the
>>> AM65-CPSW-NUSS driver:
>>> https://gist.github.com/Siddharth-Vadapalli-at-TI/5ed0e436606001c247a7da664f75edee
>>>
>>> Regards,
>>> Siddharth.
>> Hello Siddharth.
>>
>> Thanks for the log. I can read:
>> [    1.966094] Missing net_device from driver
>>
>> Did you check that nodes exist in the device tree for the net devices ?
> Yes it exists. The device-tree used was also built with linux-next
> tagged next-20240417. The node corresponding to eth0 is cpsw_port1 which
> is present and enabled in the device-tree:
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/arch/arm64/boot/dts/ti/k3-am62a7-sk.dts?h=next-20240417#n644
>
> Regards,
> Siddharth.

I could reproduce the bug by disabling 'cpsw_port2' in my device tree,
which is 'k3-am625-sk.dts' for the board I use.

A condition is missing in am65_cpsw_create_xdp_rxqs() and
am65_cpsw_destroy_xdp_rxqs() functions.

For these 2 functions, the code which is in the for loop should be
run only when port ethX is enabled. That's why it crashes with
your device tree (cpsw_port2 is disabled, which is not the case by
default for the board I developed with).

I'll send a patch to fix the issue. Thanks for reporting it.

Julien