RE: [PATCH net 1/2] r8152: fix the sw rx checksum is unavailable

From: Hayes Wang
Date: Mon Jan 09 2017 - 02:58:32 EST


Ansis Atteka [mailto:aatteka@xxxxxxxxxx]
> Sent: Tuesday, January 03, 2017 8:41 AM
[...]
> Hayes, in your iperf reproduction environment did you
> 1) connect sender and receiver directly with an Ethernet cable?
> 2) use iperf's TCP mode instead of UDP mode, because I believe that
> with UDP mode packets are more likely to be sparsely distributed?
> Also, this bug is way easier to reproduce when IP fragmentation kicks
> in because IP fragments are typically sent out very close to each
> other.
> 3) were you plugging your USB Ethernet dongle in USB 3.0 port or
> whatever Mark was using? It seems that each USB mode has different
> coalesce parameters and yours might have work "out of box"?

Yes. I connect them directly and use iperf's TCP mode. However,
I test the RTL8152 which only support USB 2.0. Therefore, I don't
think it occurs with different coalesce parameters.

> While I would not call this a proper fix, because it simply reduces
> coalescing timeouts by order of 10X and most likely does not eliminate
> security aspects of the bug, it at least made my system functionally
> stable and I don't see either of those two bugs in my setup anymore:

Do you try commit a59e6d815226 ("r8152: correct the rx early size"),
or you have used it?

Best Regards,
Hayes