Nut upsdev - Dec 2008 - ambiguous USB IDs (was: [nut-commits] svn commit r1589 - in trunk: . drivers)

On Wed, Dec 3, 2008 at 4:05 PM, Arjen de Korte <nut+devel at de-korte.org>
wrote:
> Citeren Charles Lepple <clepple at gmail.com>:
>
>> Note that this is the same VID/PID as on this example on the Lakeview
>> Research home page:
>>
>>  http://www.lvr.com/usb_on_a_budget.htm
>>
>> We can include the name "Lakeview Research" in the
documentation, but
>> we shouldn't lead people astray here.
>
> Another thing, loosely related to this, is how we are going to deal with
the
> 'generic' VID:PID combinations in some of the USB drivers, for
example the
> megatec_usb and (new) blazer_usb drivers. At present, in the megatec_usb
> driver we have several VID:PID combinations for USB-to-serial converters
> that are commonly found in UPSes. But what happens if other totally
> unrelated (non-UPS) devices use the same controllers? Or that kernel level
> support becomes available for them?
Maybe we split the udev files for ambiguous IDs into another package
(enabled at configure time, disabled by default)?
> Unless a VID:PID combination unambiguously identifies a USB device as a
> supported UPS, using it in a HAL addon is probably not a very good idea.
> Should we remove the 'hald-addon-megatec_usb' driver before
releasing
> nut-2.4?
I haven't looked much into the new structures, but could we add
another field to specify whether it is an official VID:PID, or if it
looks suspect? That could help with splitting the udev files as
mentioned above.

-- 
- Charles Lepple

On Wed, Dec 3, 2008 at 10:18 PM, Charles Lepple <clepple at gmail.com>
wrote:
>> Unless a VID:PID combination unambiguously identifies a USB device as a
>> supported UPS, using it in a HAL addon is probably not a very good
idea.
>> Should we remove the 'hald-addon-megatec_usb' driver before
releasing
>> nut-2.4?
>
> I haven't looked much into the new structures, but could we add
> another field to specify whether it is an official VID:PID, or if it
> looks suspect? That could help with splitting the udev files as
> mentioned above.
I meant to add that I, too, am against supporting bogus VID:PID
combinations in the HAL drivers.

It's supposed to be a zero-configuration system, and if someone
doesn't have a legitimate VID:PID, there is the potential for
requiring a configuration option to disable that combination later.


-- 
- Charles Lepple

Citeren Charles Lepple <clepple at gmail.com>:
> I meant to add that I, too, am against supporting bogus VID:PID
> combinations in the HAL drivers.
Not only that, but we also shouldn't support (though HAL addons)  
legitimate VID:PID combinations if these do not uniquely identify a  
supported UPS. For instance, 0665:5161 could be a supported UPS  
(megatec_usb). But since this really is the ID of a generic USB to  
serial controller, it could just as well be a GPS or a coffee machine.  
Or even worse, a UPS using a different protocol. The only way to set  
these systems up, is through a configuration file, which makes them  
unsuitable for automatic setup.
> It's supposed to be a zero-configuration system, and if someone
> doesn't have a legitimate VID:PID, there is the potential for
> requiring a configuration option to disable that combination later.
Indeed.

Best regards, Arjen
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