Re: [Qemu-devel] [PATCH] net: ne2000: check ring buffer control registers

[P J P]

  Hello Jason,

+-- On Fri, 5 Feb 2016, Jason Wang wrote --+
| I suspect this could even work. Consider after realizing, s->stop is
| zero, any attempt to set STARTPG will fail?

 Ie after 'pci_ne2000_realize'? It does not seem to set or reset s->stop 
register.
 
| This may not be sufficient, consider:
| 
| set start to 1
| set stop to 100
| set boundary to 50
| then set stop to 10

  I think any attempts to define the ring buffer limits should reset 
'boundary' and 'curpag' registers to s->start(STARTPG). I wonder if a driver 
should be allowed to fiddle with the ring buffers location inside contorller's 
memory. It does not seem right.
 
| I'm thinking maybe we need check during receiving like what we did in
| dd793a74882477ca38d49e191110c17dfee51dcc?

  Check if (s->start == s->stop) at each receive call?

--
 - P J P
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