Re: cardmgr and hotplug interplay

On Sat, Sep 28, 2002 at 06:29:57PM -0700, David Brownell wrote:
> 
> >However, after I been through both the documentation for pcmcia-cs and
> >for linux-hotplug, I'm still confused about what to expect about them
> >working together.  ...
> 
> The last time this came up, the expectation was that for 2.4 'cardmgr' would
> handle the ISA style cards (non-PCI), and hotplugging would handle CardBus
> ones (standard PCI hotplugging).

That is correct.

> As I recall things, cardmgr is tracking this issue for the (one or two...)
> PCMCIA drivers it loads.  Some of the module changes in 2.5 should IMO 
> include fixes so that driver unload can work reasonably ... it's not
> quite clear to me what's happening there.

Yes, the PCMCIA subsystem (and cardmgr) keep track of the number of
devices bound to a driver, so drivers are unloaded when there are no
longer any bound devices.

> >2) I have all respect for the work that the hotplug developers has put
> >   into the hotplug system.  But it appears that cardmgr still
> >   provides a better handling of the cardbus cards (I haven't tried,
> >   but I assume that it would be capable of removing the driver
> >   afterwards).  Is there a way letting it not try to handle cardbus
> >   cards?
> 
> I wouldn't know, but keep in mind that if you go that route you're
> suddenly in the business of maintaining lots of entries in that
> /etc/pcmcia/config file that are exactly in sync with all the
> MODULE_DEVICE_TABLE entries in the PCI drivers ... most of which
> are part of the kernel distribution, not the pcmcia package.  That
> doesn't sound very much "better"!  :)

It also isn't better (won't work) because cardmgr really only knows
how to manage drivers properly if they use the PCMCIA driver API.  It
will try to load other modules if you tell it to, but when those
modules don't register themselves as PCMCIA drivers, it gets confused.

-- Dave


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