Re: [PATCH net v2 2/2] net: bcmgenet: flatten frames that cannot fit the ring

[Florian Fainelli]

On 11/9/26 13:53, Nicolai Buchwitz wrote:
> bcmgenet_xmit() wants one descriptor more than the frame needs. A 31
> fragment frame needs 32 descriptors, so it is refused on a 32 descriptor
> ring, even if the ring is empty.
>
> As a result nothing is in flight which could wake the queue again. The
> watchdog can only hand the same frame back, therefore the queue stays
> stopped.
>
> This needs CONFIG_MAX_SKB_FRAGS >= 31 and a sender which fragments that
> finely, for example MSG_ZEROCOPY.
>
> Linearize those frames instead.
>
> Fixes: 3948b05950fd ("net: introduce a config option to tweak MAX_SKB_FRAGS")
> Signed-off-by: Nicolai Buchwitz <nb@xxxxxxxxxxx>

Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
--
Florian