Re: [lwip-users] cs8900 lost packets bug

[Paul]

Hello Leon,

I had a bit of a look for the note but can't find it. I think it was in an
technical notes white paper regarding 8 bit access and polling mode.
Anyhow I had a play without the line in my code and did not notice
any difference this makes me suspect that it only fails if you have a
slow processor and/or lots of debugging turned on with large
TX/RX buffers allocated in the cs8900 memory.

My system uses the cs8900 in polled IO mode with 16 bit
byte swapped access (big endian H8S) if would be nice if there
were switches to support this mode.

thanks

Paul


Leon Woestenberg wrote:

> Hello Paul,
>
>  
>
> > I'll track down the application / technical note for you,
> > If you can trigger a break point after a transmit fails
> > then this bug is affecting your system.
> >
> > It would like to suggest that a processor/system agnostic
> > cs8900 driver code should be implemented.
> >
> >    
> Yes. this idea has been offered by others also, in the past.
>
> What if we split the cs8900if and cs8900 functions into
> cs8900if.c/h and cs8900.c/h first?
>
> Maybe cs8900if can be generalized as a ethernet media layer for
> lwIP, whereas cs8900 can be made (more) processor independent.
>
>
> Regards,
>
> Leon
>
>  
>
> > Paul Clarke
> >
> > Leon Woestenberg wrote:
> >
> >    
> >
> > > Hello Paul,
> > >
> > > thank you very much for this report.
> > >
> > >
> > >
> > >      
> > >
> > > > buffer. This results in  poor performance as there is less memory for
> > > > incoming packets and thus lost packets.
> > > >
> > > > (Does this sound familar to anyone?)
> > > >
> > > >   
> > > >
> > > >        
> > > Our performance is poor, but that can be accounted to the microprocessor
> > > being used, non-preemptive round-robin applications and several other
> > > issues.
> > >
> > >
> > >
> > >      
> > >
> > > > The fix is described in the Crystal application notes 
> > > >
> > > >   
> > > >
> > > >        
> > > Do you know which AN?
> > >
> > >
> > >
> > >      
> > >
> > > >   <<< SET THE TRANSMIT BUFFER SIZE TO ZERO TO DEALLOCATE  MEMORY
> > > > TXLENGTH = 0;
> > > >   <<<  USE THE FORCE TRANSMIT COMMAND TO FREE THE MEMORY
> > > > TXCMD = 0x01C9U;
> > > >
> > > >   
> > > >
> > > >        
> > > Do other drivers (NetBSD, Linux) implement this as well?
> > >
> > > Regards,
> > >
> > > Leon.
> > >
> > >
> > >
> > >      
> >
> >
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> >
> >    
>
>