Blackberry support: Barry vs. usb_storage, round 2

[Chris Frey <cdfrey@xxxxxxxxxxxxxx>]

Hi folks,

Recent Blackberry devices are a rather unique breed, since they provide
multiple product ID's in one device, and a vendor-specific method
to change between them.

The usual way to perform this change is to connect to the device,
send some vendor specific control messages, and then do a
usb_set_configuration().  For Classic devices, this causes the
device to reset itself.  For Pearl devices, it waits for the host
to call usb_reset().

The problem is that the new 8830 devices will reset on
usb_set_configuration(), and a usb_reset() call will just undo the
intended mode change and go back to the state it was in when you
first plugged it in.

This causes the following race conditions between Barry and usb_storage
on most Linux systems:

	- plug in the 8830
	- usb_storage sees a Mass Storage interface, and connects with it
	- udev sees the device and runs bcharge at the same time
	- bcharge connects and sends the vendor specific control messages
	- bcharge calls usb_set_configuration() and nothing happens
		since usb_storage has an interface claimed
	- normally this is ok, for the Pearl, and bcharge calls
		usb_reset(), which sets the mode and everyone is happy...

But...

	- for the 8830, usb_reset() goes back to the start, the mode is
		not changed, and there is no way to change it while
		usb_storage has Mass Storage claimed, since the mode
		change occurs on usb_set_configuration().

Questions:

	- is there a safe way to delay usb_storage, perhaps from udev,
		so that when Barry is installed the mode is changed
		before usb_storage looks for a drive?

	- is there a better way to handle this?  perhaps force usb_storage
		to release the interface somehow, since this only happens
		when the device is first plugged in?

Ideas and comments welcome!

Thanks in advance,
- Chris


-------------------------------------------------------------------------
SF.Net email is sponsored by: The Future of Linux Business White Paper
from Novell.  From the desktop to the data center, Linux is going
mainstream.  Let it simplify your IT future.
http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4
_______________________________________________
linux-usb-devel@xxxxxxxxxxxxxxxxxxxxx
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel