[sane-devel] This is HOT (-plug related)

[Michael Herder]

Henning Meier-Geinitz, Sonntag, 17. November 2002 20:10:
> > over the last weeks, I've read a couple of times, that in order to get
> > the scanner module loaded (hotplug), one should add an entry to
> > /etc/hotplug/usb.distmap.
> > However, on all systems I've tried this, I had to add an entry to
> > /etc/hotplug/usb.handmap.
> > Can someone please explain, where one has to add what, when and why?
> > (or point me to the documentation which probably exists somewhere :-)
>
> Copied from usb.agent (the file that actually is called on USB hotplug
> events):
...
> So I guess handmap is correct for kernel 2.4 (untested).

Ok, thanks. Now the situation is like this:

Hotplug and the scanner module

1. Scanner module "knows" product/vendor id
1.1. Recent kernels (beginning with version 2.4.12 ?)
In this case, there's nothing the user has to care about. An entry gets added 
to /lib/modules/<kernel_version>/modules.usbmap when running depmod -a, and 
the scanner module is modprobed automatically when the system is booted or 
the scanner is plugged-in.
1.2. Other kernels
On system without modules.usbmap, the user has to ensure, that an entry for 
the device is present in /etc/hotplug/usb.distmap.

2. Scanner module doesn't "know" product/vendor id
In this case, a correct entry must be added to /etc/modules.conf:
options scanner vendor=<vID> product=<pID>

2.1. Recent kernels (beginning with version 2.4.12 ?)
On systems, where /lib/modules/<kernel_version>/modules.usbmap gets created 
when running depmod -a, /etc/hotplug/usb.distmap isn't used at all by the 
hotplug utilities. An entry for the device with the correct vendor/product id 
must be added to /etc/hotplug/usb.handmap instead.
2.2. Other kernels 
On systems without modules.usbmap, the user has to ensure, that an entry for 
the device is present in /etc/hotplug/usb.distmap.

Is this correct ?
Btw, why do I need (see 2 and 2.1) an entry in modules.conf? Shouldn't the 
module get modprobed with the vid/pid from usb.handmap in this case?

Thanks,
Michael