Re: [lwip-users] Automatic DMA pbuf ring replenish

[Kieran Mansley]

On Sat, 2011-10-29 at 11:23 +0200, Timmy Brolin wrote:
> When writing a DMA based ethernet driver, a function must be written
> to periodically allocate POOL pbufs and put them in the Rx DMA buffer
> descriptor ring.
> 
> I think this could be made a bit more efficient.
> What if I make the Rx DMA buffer descriptor ring large enough to hold
> all POOL pbufs. At start-up all POOL pbufs are allocated and put in
> the Rx DMA ring.
> pbuf_free() is modified so that whenever a POOL pbuf is freed it is
> immediately put in the Rx DMA ring.

Worth trying.  I think it is based on the assumption that pool pbufs are
only used for DMA RX.  I'm not sure if this assumption holds on all
systems.

Kieran