On Thu, 11 Dec 2008 13:07:28 +0000
Jarek Poplawski <jarkao2@gmail.com> wrote:

quoted text
> On 09-12-2008 22:06, Neil Horman wrote:
> ...
> > When executing napi->poll from the netpoll_path, this bit will
> > be set. When a driver calls netif_rx_complete, if that bit is set, it will not
> > remove the napi_struct from the poll_list.  That work will be saved for the next
> > iteration of net_rx_action.
> 
> This could be not enough: some drivers, e.g. sky2, call napi_complete()
> directly.
> 

There is good reason for this. Although most drivers only have one NAPI
instance per device, and multiqueue drivers have several NAPI structures
per device, a few devices like sky2 need to support multiple devices
running off one NAPI receive. The Marvell hardware has a common receive
interrupt for both ports on a dual port card.

This kind of hardware limits usage of netpoll. Only one port can be
used with netpoll because netpoll makes assumptions about NAPI
association.
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