Re: usb coldplug problem

[Bernd Porr <berndporr@f2s.com>]

I totally take Greg's point that the firmware load should be via a 
firmware request from the driver which then in turn triggers the 
firmware helper in userspace. When I checked that last time (about a 
year ago) this was too buggy and I stuck with the comedi firmware upload 
which has been running for about 4 years without probs. Might be a good 
time to use the firmware helper.

But in comedi it is so that the command "comedi_config" associates a 
driver with a device. This works fine with hotplug. I plug in my usbdux, 
this triggers a udev event and then a udev rule can decide which 
/dev/comedi? is actaully taking care of the box. If you want to question 
that mechanism then comedi itself has to be rewritten. And I'm sure that 
nobody here in comedi-land would like to do that. It just works too good.

 > Why cannot be the /proc interface be used.
Can you explain that a bit more.

Thanks!

/Bernd

Sujit Karataparambil wrote:
> We need to call the rule in the kernel context as 'greg' was saying.
> 
> Seems to be the correct way to be the firmware upload via USB.
> 
> On 12/3/08, Kay Sievers <kay.sievers@vrfy.org> wrote:
>> On Wed, Dec 3, 2008 at 09:40, Bernd Porr <berndporr@f2s.com> wrote:
>>
>>>> Yes it will as the startup scripts already know how to handle coldplug
>>>> firmware events.
>>> To give the "magic" a name: you mean udev adm trigger? Or a nice script
>>> which writes "add" to all "uvents"? This is exactly what doesn't work. There
>>> are absolutely no udev events generated for comedi during boot. I've checked
>>> that now thoroughly and I think there's something wrong. What could that be?
>> How does the "device" look like in sysfs, where you want to hook into
>> with the userspace setup?
>>
>> Kay
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> 
> 

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