Re: [PATCH] [2.6] Clean up SL811 headers

[David Brownell <david-b@pacbell.net>]

Kyle Moffett said:
> The USB SL811 host has a structure stuck in linux/usb_sl811.h  As this
> structure is kernel private and only used by a single piece of code, 

That's very wrong ... the structure in question is the interface between
the board-specific setup and the driver (as it says in the comment).  A
better way to put the situation is that www.kernel.org doesn't currently
bundle support for a board that wires that chip into its platform_bus.


> this patch moves it to the header file from which it is used, deleting the 
> old one.

Here's a thought experiment for you ... do that for EVERY driver
on the platform_bus, and see how quickly you get a big mess.
Board support packages on 2.4 tended to take that approach;
good riddance, IMO.

When you take that approach, then adding support for a new
board means ** CHANGING EVERY DRIVER USED WITH THAT BOARD **
to know how the chip is set up on that particular board.
IRQs, addressing, CPU and GPIO pin multiplexing, support
logic ... yeech!

Better to have a single arch/XYZ/mach-ZYX/board-ABC.c file that
just sets up the relevant platform devices, and the platform_data
those drivers use.  The board support packages should be small,
mostly using standard drivers ... not be invasive monsters.

- Dave