Re: [PATCH] usb.agent should processes usermap before other

["Maksim (Max) Krasnyanskiy" <maxk@qualcomm.com>]

>>Currently usb.agent processes usermap after the kernelmap. Unfortunately 
>>it doesn't work for
>>Broadcom USB (BCM) firmware loader. The problem is that Bluetooth HCI USB 
>>driver (hci_usb)
>>has to claim any device with proper Bluetooth class, subclass and 
>>protocol regardless
>>of the vendorid/productid. But at the same time fw loader has to be able 
>>to claim devices
>>with specific vendorid/productid even if they have proper Bluetooth 
>>class, subclass, proto.
>
>If hci_usb shouldn't be claiming specific devices, it's simple
>to teach it not to do so.   I notice it's not using driver_info
>for anything, so it'd be easy to store flags there telling it
>not to bind to the pre-firmware IDs (idProduct = 0x2033); then
>the with-firmware path would work normally (idProduct = 0x2000).
>
>That'd total about half a dozen lines:  define the flag, add a
>MODULE_DEVICE_TABLE entry to blacklist that one device, add code
>in the probe() routine to test that flag and return if it's set.
Yeah, I was gonna do that anyway because processing usermap first doesn't help
when driver is already loaded.
I thought it might be nice if USB core could do that ie something like
USB_IGNORE_DEVICE(xxx, yyy) in the driver id_table. But Johannes  pointed out
that it probably won't be useful for other drivers.

>>So, the solution is to process usermap first. It kinda makes sense anyway,
>>usermap should have priority over kernelmap.
>
>No can do ... remember that when drivers are statically linked,
>the kernel is going to get first whack regardless of what you
>try to make userland do.  Changing that isn't an option today,
>and wouldn't IMO be a good idea in any case.
>
>That means you must make the kernel driver bind correctly,
>or in the case of this no-firmware device, not bind.
I was gonna say that it would not work but then I noticed that
it's actually fixed in 2002.04.01.
usb.agent that came with RH 7.2 was doing
         if [ "$FOUND" = "false" -a -r $MAP_USERMAP ];
Which means that usermap won't be processed if kernel driver exists
for this device, even if driver ignores these particular ids.
I didn't notice that you guys got rid of FOUND = false check in
latest usb.agent. Now that this check isn't there it should work
correctly if driver ignores pre-fw ids.

Max



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