LWIP buffer alignment

[Jerome Forissier]

Hi Tim,

On 9/5/25 19:45, Tim Harvey wrote:
> Hi Jerome,
> 
> I'm working with a board that has an IMX ENETC MAC on it
> drivers/net/fsl_enetc.c and when configured for LWIP it fails and
> warns about RX buffers not being 64B aligned:
> WARNING at drivers/net/fsl_enetc.c:776/enetc_setup_rx_bdr()!
> 
> I tried changing MEM_ALIGNMENT to 64 in lib/lwip/u-boot/lwipopts.h but
> that did not align the buffers to 64B. Where are the lwip buffers
> created and do you have any suggestions for working around this?

The LwIP RX buffers are created in net-lwip.c. See eth_init_rings().
You might have PKTSIZE_ALIGN and/or PKTALIGN set wrongly.

Regards,
-- 
Jerome

> 
> Best Regards,
> 
> Tim