On Tuesday 21 February 2006 21:32, Christoph Hellwig wrote:

On Tue, Feb 21, 2006 at 09:24:23PM +0100, Carlos Mart?n wrote:

quoted

Wouldn't this lead to duplicated function definitions at link time if both 

are 

quoted

compiled-in? From your module split above I understood you wanted 

acx-common 

quoted

to be another module, but here I see it goes into the modules.

No.  The above makefile fragment builds three modules: acx-common.o,
acx-pci.o and acx-usb.o as mentioned above.  The magic here is that with
that makefile fragment is that the kbuild systems builds acx-common.o if
either CONFIG_ACX_PCI or CONFIG_ACX_USB is set, and even makes sure to
do the right thing if either is builtin.  There is not code duplication
at all.

Then all is good.

quoted

quoted

---- snip ----

 - kill the IS_PCI/IS_USB macros and add a acx_operations structure that
   handles the different hardware without branches all over and allows
   the hw-specific code to be in separate modules.

There aren't that many IS_{PCI,USB} uses and most if not all are justified 
(extra step for one case). It might be a good idea to do that for the 
IS_ACX{100,111} macros instead of calling the generic function which then 
calls the chip-specific one.

The important bit is that you need the pointers with the above module
spit, because you can't call usb- or pci-specific routines from 
acx-common.ko 

Yes, I realise that (unless you export them, but I don't think we want that). 
I've started this, but I think it'll probably be next week before I have time 
to really work on it.

This approach is probably better even if the driver is unified. Pointer 
dereferences are cheaper than branches/jumping, aren't they?

   cmn
-- 
Carlos Martín Nieto    |   http://www.cmartin.tk
Hobbyist programmer    |


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