Alan Stern schrieb:
On Wed, 4 Nov 2009, Oliver Neukum wrote:
If power is turned off, there's nothing we can do about it. Once that
happens, it doesn't make much difference whether the mode switch occurs
in usb-storage or from a userspace program. The old device instance
will go away and a new one will appear.
That is what happens and what must happen if we switch mode in user space.
In kernel space, the kernel could repeat the mode switch.
How? Doesn't the mode switch cause a change in the configuration,
interface, or endpoint descriptors? The end result would be the same
-- the old device instance would go away and a new one would appear.
That is exactly what my "Option" modem is doing. There is no
difference if I use "option_ms" in the kernel or the external
program to switch it. It's always "USB disconnect" and "usb-storage:
device found".
Same thing happens if I trigger a reset in the *switched* device via
libusb (but not in the 'default' state).
Josua Dietze
--
Man is the only creature on earth enabled to take a
warm meal while flying! Loriot
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