[Ftdi-usb-sio-devel] Back porting questions

[Mike R. <er...@es...>]

Howdy Bill,

I tried 2.4 on my system, and it took me a few days to recover from
all the things that broke.  So I recompiled my 2.2.20 kernel to be
modularized instead of monolithic and read thru some of the ftdi_sio.c
code.  One thing it wants is a header byte, 6 bits of size and '01'
on the end.  So I fed that into my serial stream, and data is flowing
thru the 2.2.20 usb-serial, my scope is happy, my PIC sees data (tho
I'm not yet sure it sees the correct data...) and it looks like it works!

What I'd like to do is get rid of the header byte, at least from the
serial port view of things.  How did you eliminiate this in the 2.4
version?  The header byte is sent all the way thru in my loop back
test - I just have the PIC send back exactly what it sees.  Since I
get the same number of reads and writes as there are bytes sent via
the serial write, it's clear that the header byte is being sent
all the way down the chain.  Eliminating it shouldn't hurt, and at
worst I can force the system to do fixed size block transfers.

With the modular kernel I should be able to patch the ftdi_sio.c
to work the same as the 2.4 version, at least from the write()
level.  Any hints you have on how to do that would be very much
appreciated!

Patience, persistence, truth,
Dr. mike