Re: Puzzling driver problem

[Ben Hutchings <bhutchings@solarflare.com>]

On Tue, 2009-05-12 at 00:13 -0400, David H. Lynch Jr. wrote:
> I am working on a driver for the Xilinx Local Link Fifo Temac.
>     It is based on an earlier driver for very similar hardware that uses
> a scatter gather DMA engine rather than a FIFO.
>     95% of the code is common.
>     The FIFO code is also tested independently in a bootloader and works
> fine there.
> 
>     The problem I am having is that after the driver and linux load.
>     HTTP requests to the busy box web server hang after just a few HTTP
> packets.
>    
>     Many other protocols seem to be working just fine. I can send
> thousands of pings and get responses,
>     I can SSH to the embedded linux running the driver.
>     Using a packet sniffer (wireshark) aside from the HTTP stalling,
> nothing looks extrodinary.
>     Other packets are getting through and being replied
[...]

Is it possible that you are setting the maximum frame length
incorrectly?  HTTP is likely to use maximum-length frames for responses
whereas ping, SSH (aside from file transfer) and TFTP will use smaller
frames.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
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