[tulip] Changing MAX_UNITS to a configurable value?

[Ben Greear]

Donald Becker wrote:

> On Sun, 23 Dec 2001, Ben Greear wrote:
> 
> 
>>I find myself wanting to run gobs of 4-port NICs in my
>>machines
>>
> 
> This is a very unusual requirement.  It's reasonable to expect someone
> with such a configuration to modify documented constants at the top of
> the source file.


Perhaps, but if I can make it configurable through the xconfig process,
it will be much easier to explain to potential customers of mine.  For
some reason, editing source code scares some people :)  As long as we
default to decent values, and have help information in the config process,
I don't see any problems with the extra configurability...

Actually, it would probably make more sense to have some more global
settings that influenced all (most) drivers.  For instance, for buffer
sizes: 'small', 'big', 'huge'  (and let individual drivers deal with
their internals to keep powers-of-two and/or cache alignment tweakings
in order...)  We could have another setting to influence the number of
devices the drivers can support 'few' /* 0-4 */, 'several' /* 0-8 */,
'many' /* 0-24 */, 'bunches'/* 0-64 */


> 
> 
>>and the tulip driver (in 2.4.17), by default, will
>>handle only 8.  There is a #define (MAX_UNITS) that looks
>>like it will raise this number to, say, 32.....
>>
> 
> Check carefully: this is a limit only on the number of interfaces that
> you can pass module options to, not the number of supported interfaces.
> 
> #define MAX_UNITS 8		/* More are supported, limit only on options */


Hrm, maybe I have a PCI/Card problem then.  I see 8 ports (two of the 3 4-port
NICs), but not the last 4 ports.  lspci does not show them either.  Does that
mean anything to you?


> 
> 
>>To keep from having to change source code, I'd like to either
>>make the max-units a module parameter, or a compile time
>>option in 'make xconfig'.
>>
> 
> The reason for the limit is that each module option needs a initialized
> array element.


So, it's just a memory usage issue, correct?

Thanks for the feedback,
Ben



-- 
Ben Greear <greearb@candelatech.com>       <Ben_Greear AT excite.com>
President of Candela Technologies Inc      http://www.candelatech.com
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