sample USB Driver / Probe not getting called

[selvamuthukumar v]

On Mon, Oct 17, 2011 at 4:12 PM, Abhijit Pawar <apawar.linux at gmail.com> wrote:
> On 10/17/2011 04:08 PM, selvamuthukumar v wrote:
>>
>> On Mon, Oct 17, 2011 at 3:05 PM, Abhijit Pawar<apawar.linux at gmail.com>
>>  wrote:
>>>
>>> Hi All,
>>> Is there any way to call a sample USB driver whenever a USB device is
>>> attached to the system irrespective of the class and type of the device?
>>>
>>> To do this, LDD3, chap 13 mention that for USB device table, we only
>>> need to add the driver_info entry as 42.
>>>
>>> However if I do this, my probe is never getting called.
>>>
>>> Now, I give the vendor and product id of this Mouse to the device_id
>>> table and load my driver again. Still the probe is not getting called.
>>>
>>> Is it that USB core is getting the proper driver for this mouse before
>>> my driver entry in the list?
>>>
>>> Am I missing something?
>>>
>> probe function will get called only if no other driver is attached to
>> the device. Make sure the device does not have any other driver.
>> Please refer line 290 and 291.
>>


>> 290         if (!dev->driver)
>> 291                 driver_probe_device(drv, dev);
>
> Thanks for reference to this function. It seems that there isnt any way to
> override the already attached driver to the device.
> Is there any?
>

If already bounded driver is compiled as module you can rmmod. But
overriding option is not given may be because, the current loaded
driver may be doing an important operation, interrupting it may leave
the device in undefined state.