On Mon, 28 Mar 2005, Patrick Mochel wrote:
> How is this related to (8) above? Do you need some sort of protected,
> short path through the core to add the device, but not bind it or add it
> to the PM core?
Having thought it through, I believe all we need for USB support is this:
Whenever usb_register() in the USB core calls driver_register()
and the call filters down to driver_attach(), that routine
should lock dev->parent->sem before calling driver_probe_device()
(and unlock it afterward, of course).
(For the corresponding remove pathway, where usb_deregister()
calls driver_unregister(), it would be nice if __remove_driver()
locked dev->parent->sem before calling device_release_driver().
This is not really needed, however, since USB drivers aren't
supposed to touch the device in their disconnect() method.)
With that change in place we can guarantee that every time a USB driver's
probe() is called, both the interface and the parent device are locked.
I don't know how cleanly this can be implemented. You probably don't want
to lock dev->parent->sem every time, only when needed. Maybe the simplest
approach would be to add a flag in struct bus_type, which could be set for
the USB bus_type and clear for everything else.
Alan Stern
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
