[PATCH] net: airoha_eth: increase max mtu to 9220 for DSA jumbo frames

[Benjamin Larsson]

On 16/01/2026 15:56, Andrew Lunn wrote:
> On Fri, Jan 16, 2026 at 08:09:51PM +0530, sayantan nandy wrote:
>> Hi all,
>>
>> Thanks for the review and comments.
>>
>> I checked the AN7581 HW and it does support MTU sizes up to 16K. However, as
>> mentioned by Benjamin, larger packets consume more DMA descriptors, and while
>> no extra buffers are allocated, this can put pressure on the descriptor rings.
> Does the hardware consume DMA descriptors for the full 16K, not just
> the number of descriptors needed for the actual received packet size?
> That seems like a bad design.
>
>        Andrew

The descriptor buffer size is configurable. The amount of used 
descriptors will be the received packet size % descriptor buffer size + 1.

MvH

Benjamin Larsson