|Sam Lawrance||Mar 25, 2004 3:26 pm|
|Bernd Walter||Mar 25, 2004 11:49 pm|
|M. Warner Losh||Mar 27, 2004 3:56 pm|
|Bernd Walter||Mar 27, 2004 4:25 pm|
|M. Warner Losh||Mar 28, 2004 12:30 am|
|Bernd Walter||Mar 28, 2004 2:49 am|
|Sam Lawrance||Mar 29, 2004 6:33 pm|
|M. Warner Losh||Mar 29, 2004 6:44 pm|
|Bernd Walter||Mar 30, 2004 12:41 am|
|M. Warner Losh||Mar 30, 2004 12:46 am|
|Bernd Walter||Mar 30, 2004 1:13 am|
|Sam Lawrance||Mar 31, 2004 4:55 am|
|M. Warner Losh||Mar 31, 2004 9:11 am|
|Bernd Walter||Mar 31, 2004 10:16 am|
|Subject:||usbd config file parse behaviour|
|From:||Sam Lawrance (bor...@brooknet.com.au)|
|Date:||Mar 31, 2004 4:55:24 am|
On Tue, Mar 30, 2004 at 01:46:32AM -0700, M. Warner Losh wrote:
In message: <2004...@cicely12.cicely.de> Bernd Walter <tic...@cicely12.cicely.de> writes: : On Mon, Mar 29, 2004 at 07:44:34PM -0700, M. Warner Losh wrote: : > In message: <1080613926.1125.6.camel@dirk> : > Sam Lawrance <samu...@studentmail.newcastle.edu.au> writes: : > : On Sun, 2004-03-28 at 20:47, Bernd Walter wrote: : > : > On Sun, Mar 28, 2004 at 01:31:03AM -0700, M. Warner Losh wrote: : > : > > Btw, any interest in making it possible to kldload a usb module and : > : > > having device attach to it? Right now the usb code assumes that you : > : > > can unplug the device and replug it back in. I have at least two : > : > > devices on my laptop that can't be removed (bluetooth and memory stick : > : > > reader), so I can't dynamically load drivers for them... : > : > : > : > I'll think about it. : > : > Reprobing is not so much an issue as selecting an interface for it. : > : : > : would this done by filling in uhub_driver_added() to find a better : > : driver match for a device and reattaching? : > : > Yes. Actually, it also requires some changes to newbus as well to : > allow for rebidding of devices. And there's some minor resetting of : > the device that likely needs to happen, but that's lower priority. : : Don't forget that we already have a driver for every USB device: ugen(4) : We need a better trigger to reprobe drivers - thats the real problem.
No. That's not the real problem here. The real problem here is that uhub doesn't implement the driver_added callback correctly. The ugen issue, while interesting, can be overcome by not having ugen in the kernel.
Not having ugen in the kernel is not an option. I can't say that I really like the problems introduced by ugen, but since I have no better idea and ugen is widely used - even by me.
When ugen is in the kernel, we do need to do the rebid thing in newbus, which we don't do, but there's little point in fixing one w/o fixing the other.
You can't kldload a new driver and reshuffeling all ugen instances. They are possibly used and probing for USB devices requires exclusive access in many cases.
I'm more thinking about some kind of userland tool that allows retriggering an USB device in a controlled way. Such a feature is required for some types of firmware downloaders too. Intelligent USB chips requireing firmware download could disconneect and reconnect themself from the bus e.g. the TI-TUSB* family, but there are still others in the wild. I've seen firmware downloaders to do evil things as reseting an USB ports on their own, which is quite dangerously as it introduces a race for having multiple devices with address 0 (the default for freshly attached ones).
I agree that it's bad to yank a device from under ugen automatically and reattach it to a better match. How about adding a new ioctl on /dev/usb, eg USB_REPROBE to reset a device if a better match exists? Could tack an option on to usbdevs to call it on requested devices.