Re: usbd doesn't get DEVICE_DETACH? (plus patch for typo in usbd.c)

From: Vladimir B. Grebenschikov <vova_at_sw.ru>
Date: Fri, 24 Oct 2003 00:39:31 +0400
÷ ÐÔ, 24.10.2003, × 00:01, Vladimir B. Grebenschikov ÐÉÛÅÔ:
> ÷ ×Ô, 21.10.2003, × 10:45, Johny Mattsson ÐÉÛÅÔ:
> > Hi all,
> 
> Me too !
> 
> kern/46488  
> 
> I will check your patch.

Yes, patch works, Thanx, please commit and close PR.

Now I can get rid of hack in usbd.conf:
---
# hack to workaround no keyboard detach event
device "HUB"
        devname "uhub[0-9]+"
        detach "/usr/sbin/kbdcontrol -k /dev/kbd0 < /dev/console"
---


> > BACKGROUND:
> > After a recent purchase of a Palm Tungsten W, I've been spending a few 
> > hours getting the synchronization working in FreeBSD (which hasn't been 
> > an easy task). I've almost got it all up and running, by using a PPP 
> > over Serial over USB setup, but I have a small problem remaining.
> > 
> > THE PROBLEM:
> > Basically, what's happening is this: When I initiate the sync on the 
> > Palm, it lights up the USB port and a /dev/ucom0 is created for me. My 
> > usbd then launches a ppp instance for that port, as well as the service 
> > daemon for the Palm device. This is all well and wonderful. However, 
> > when the sync is complete, the Palm closes down the USB port (to be 
> > expected), and /dev/ucom0 is removed. The problem is that the usbd only 
> > sees a DRIVER_DETACH, not a DEVICE_DETACH message, and because of that, 
> > it doesn't execute the "detach" statement for ucom0 (in my case, to shut 
> > down ppp and the service daemon). The net effect is that I get a ppp 
> > hanging around and getting in the way for the next sync.
> > 
> > 
> > SPECIFIC QUESTION:
> > What I'd like to know is whether usbd should pick up on the implicit 
> > device detach in the DRIVER_DETACH event (probably won't work if there's 
> > more than one device hanging off the driver detaching), or if there 
> > should indeed be a DEVICE_DETACH arriving before the DRIVER_DETACH?
> > 
> > If I read usb.c correctly, it appears that when a detach event is 
> > posted, any events in the queue with the same cookie will be discarded. 
> > Is this intended behaviour, or should DEVICE_DETACH messages be left in 
> > the queue for normal processing? For me it would make more sense if they 
> > were kept, but I don't have any previous exposure to this code, so I'm 
> > not an authoritative voice exactly.
> > 
> > As can be see in the trace below, the DRIVER_DETACH event does contain 
> > the device name, so it would be easy to modify usbd to handle this 
> > scenario as well. It doesn't feel like a very elegant way to do things, 
> > though, and as I mentioned above, it probably can't deal with the case 
> > where there's more than one device handing off the detaching driver.
> > 
> > If someone points out what would be the preferred way of resolving this, 
> > I'm happy to get a patch happening.
> > 
> > Trace showing that there's no device-detach picked up by usbd:
> > ====
> > usbd: processing event queue on /dev/usb
> > usbd: driver-attach event cookie=3217029324 devname=ucom0
> > USB_EVENT_DRIVER_ATTACH
> > usbd: processing event queue on /dev/usb
> > usbd: device-attach event at 1066715435.318666000, Palm Handheld, Palm, 
> > Inc.:
> >    vndr=0x0830 prdct=0x0031 rlse=0x0100 clss=0x0000 subclss=0x0000 
> > prtcl=0x0000
> >    device names: ucom0
> > usbd: ucom0 matches ucom0
> > usbd: Found action 'Palm Tungsten W' for Palm Handheld, Palm, Inc. at ucom0
> > usbd: action 0: Palm Tungsten W
> >    vndr=0x0830 prdct=0x0031
> >    devname: ucom0
> >    attach='/usr/sbin/ppp -auto palm; /usr/local/bin/pi-csd -H sarah -a 
> > 192.168.2.3 -n 255.255.255.0'
> >    detach='killall ppp; killall pi-csd'
> > usbd: Setting DEVNAME='ucom0'
> > usbd: Executing '/usr/sbin/ppp -auto palm; /usr/local/bin/pi-csd -H 
> > sarah -a 192.168.2.3 -n 255.255.255.0'
> > Working in auto mode
> > Using interface: tun0
> > /usr/local/bin/pi-csd(50923): Connection Service Daemon for Palm 
> > Computing(tm) device active.
> > /usr/local/bin/pi-csd(50923): Accepting connection requests for 'sarah' 
> > at 192.168.2.3 with mask 255.255.255.0.
> > /usr/local/bin/pi-csd(50923): Connection from [192.168.2.253], req 
> > 'sarah', 192.168.2.3, 255.255.255.0 = accept.
> > /usr/local/bin/pi-csd(50923): Connection from [192.168.2.253], req 
> > 'sarah', 192.168.2.3, 255.255.255.0 = accept.
> > /usr/local/bin/pi-csd(50923): Connection from [192.168.2.253], req 
> > 'sarah', 192.168.2.3, 255.255.255.0 = accept.
> > Terminated
> > usbd: '/usr/sbin/ppp -auto palm; /usr/local/bin/pi-csd -H sarah -a 
> > 192.168.2.3 -n 255.255.255.0' returned 143
> > usbd: driver-detach event cookie=3217029324 devname=ucom0
> > USB_EVENT_DRIVER_DETACH
> > usbd: doing timeout discovery on /dev/usb0
> > usbd: doing timeout discovery on /dev/usb1
> > ====
> > 
> > Oh, and there's a typo in usbd.c too, it's printing DETACH when the 
> > event is ATTACH. One-line patch to fix this is ATTACHed (pun intended).
> > 
> > Cheers,
> > /Johny
-- 
Vladimir B. Grebenschikov <vova_at_sw.ru>
SWsoft Inc.
Received on Thu Oct 23 2003 - 12:05:59 UTC

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