2.4.30 - USB serial problem

[Ian Leonard <ian@smallworld.cx>]

Greetings,

We recently upgraded from 2.4.24 to 2.4.28 and the problem described 
below appeared. I have tested it on 2.4.30 and the fault still exists.

It is something to do with usb serial. We are actually using the 
ftdi_sio module but a quick diff suggests it hasn't changed much. I am 
not 100% sure what is going on but we are sending out various short 
commands (11 bytes) to an external device. Most work just fine but one 
using one sequence seems to cause the driver to loop and continually 
send out the same command. The application keeps sending other commands 
but eventually the write () blocks and that's that.

Examining the packet that caused the problem showed it was very similar 
to the others but it contained 0x0a. This obviously stuck out as being a 
candidate for some sort of translation problem.

I also built a 2.4.28 kernel with the ftdi_sio and usbserial code from 
the 2.4.24 release. It also failed. This was a surprise and I am 
wondering of I did it correctly.


I don't have the failing equipment with me here but will return to site 
next week. I would appreciate any words of wisdom on the problem.


-- 
Ian Leonard

Please ignore spelling and punctuation - I did.