Re: [lwip-users] LWIP 1.2 issue.

[Jonathan Larmour]

Robert Morse wrote:
> On a side note: I am using a AM79C960 like ethernet chip, that uses DMA
>  buffers, my question, on a transmitted packet, I do not know if it was
>  transmitted ok until an interrupt is generated (both
> receive/transmit).  I can then look at some flags to see the state of
> the transmitted buffer. If I get an error back saying that the packet
> was not transmitted correctly, how should I pass that back up the stack
> so the packet can be retransmitted.  Now, I don't think I want to wait
> in the low_level_output() of the driver, until the packet has been
> fully transmitted, as that would eliminate any buffering that the
> ethernet chip can do.  I have the AM79C960 setup for 16 transmit
> buffers.  Just a quick question.

Either you attempt to resend the failed packet inside the driver 
immediately on an error indication[1], or you let higher layers retransmit 
it in their own time. You don't pass anything up to the stack to get it to 
retransmit.

Jifl
[1] Probably only a limited number of times though.
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