Re: [bisect] kernel 2.6.38 regression with root nfs mounting

[Will Simoneau]

On 09:26 Fri 25 Mar     , Chuck Lever wrote:
> 
> According to the trace, the mount succeeds, and NFS requests are working.  However, the server's replies to READ requests are not being seen by the client.  Something on the client host or in the network is dropping them.  I see successful 16KB reads, but 32KB reads do not work.  Check your client for packet filtering (either intentional filtering, or accidental filtering due to configuration issues).
> 
> I'll revisit the mount option defaults for NFSROOT again.

I have encountered the same problem as Belisko, using an FPGA board I am
working on (CPU is a mipsel r4k clone). 2.6.38-rc8 nfsroot works fine,
2.6.38 hangs while starting init. I can see read replies going out from
the NFS server but the client does not seem to receive them.

Interestingly, we are both using DM9000 network chips. I wonder if there
is a UDP-related problem on the DM9000. I will play with my
configuration a little more (in particular testing proto=tcp and revert
of 53d4737580535e073963b91ce87d4216e434fab5) but my guess is the DM9000
driver/chip is to blame. The DM9000A on my board has 16K of on-chip SRAM
used for its RX/TX buffers which may be playing a part in the problem.

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