Question on ue devices autoconfigure versus Linux.
Jesus Monroy
jessemonroy650 at yahoo.com
Sat Nov 29 20:41:05 UTC 2014
Alfred,
As you may recall, at Anybots USB was the backbone of our bot.
And as no one wanted to tackle the USB, besides John and I,
it fell to me to read the Spec. John can tell you as much as I
can USB is a basket case and a bastard child.
To accomplish your task I would suggest running your
task in user space (with privileges of course).
USB requires timing, negative-timing, fallbacks and timeouts.
It is not pretty. Perhaps in 5-10 years we can kill the
negative-timing and fallbacks, with some confidence
that USB 1.0 are no longer available and cannot be
plugged in to new devices.
timing, fallbacks and timeouts are straightforward.
negative-timing requires that you guess if a 1.0 device
might have been attached to bus. Most MFGs ignore
this, and either fuck the device or fuck the bus. Recovery
requires that your USB bus (or hub) allows you to reset it.
Which if you've fucked the bus, means you have to
guess when the device was removed and recover
in a normal method.
Hope this helps.
Jesse
--------------------------------------------
On Fri, 11/28/14, Alfred Perlstein <alfred at freebsd.org> wrote:
Subject: Re: Question on ue devices autoconfigure versus Linux.
To: "Jesus Monroy" <jessemonroy650 at yahoo.com>, usb at freebsd.org
Cc: "Hans Petter Selasky" <hselasky at FreeBSD.org>
Date: Friday, November 28, 2014, 6:16 PM
Well sure, but we have devd in
FreeBSD for some time. It actually does
handle the hot plug (sort-of...) I made a custom devd hook
for it.
The actual problem is that if I boot FreeBSD with the device
plugged in
then devd never runs my hooks.
That and I'm not sure if devd is even the right place... to
put my
hooks, but it sure seems like it... except for the "doesn't
show up at
boot".
Also really interested in knowing how the heck Linux figures
out the IP
address?
Is there some usb ethernet spec for autoconfiguring???
-Alfred
On 11/28/14, 5:05 PM, Jesus Monroy wrote:
> Alfred,
> I usually don't get the USB mailing list in my inbox.
However,
> for some reason I fished this out of spam. Indicating
to me
> I should answer this.
>
> THE ANSWER:
>
> Hot swapping has never been a strong point for BSD.
> Basically they think, "hot swapping" means, flip a
> mechanical switch, remove the device. They DON'T
> think like a USB device; which is "plug in and pull"
> - at will.
>
> In the Linux world, there is an army of people that
> attack problems like this 'ad hoc'. The BSD
> community is far too formal to get it done in
> any reasonable time frame.
>
> In the Linux world, there are a host of "post-boot"
> solutions, such as systemd, busd, etc. They all
> generally trap an event, be it real (such as an IRQ),
> network, program, or user. This is usually
> leverage by /proc, dmesg or similar.
>
> Hope this helps.
> FWIW: I'm living in El Paso Texas for the next 6
months.
>
> Best of Luck,
> Jesse
>
>
> --------------------------------------------
> On Fri, 11/28/14, Alfred Perlstein <alfred at freebsd.org>
wrote:
>
> Subject: Question on ue devices
autoconfigure versus Linux.
> To: usb at freebsd.org
> Cc: "Hans Petter Selasky" <hselasky at FreeBSD.org>
> Date: Friday, November 28, 2014, 5:37
PM
>
> Hello,
>
> We have a widget here, basically a
"beagleclone" that runs
> Linux.
>
> When I plug it into an ubuntu host it
shows up as:
>
> usb0 Link
encap:Ethernet HWaddr
> 8a:18:9f:c4:a9:02
> inet
> addr:169.254.99.129
Bcast:169.254.99.131
> Mask:255.255.255.252
> inet6
addr:
> fe80::8818:9fff:fec4:a902/64
Scope:Link
> UP
BROADCAST
> RUNNING MULTICAST MTU:1500
Metric:1
> RX
packets:3
> errors:0 dropped:0 overruns:0 frame:0
> TX
packets:56
> errors:0 dropped:0 overruns:0
carrier:0
>
collisions:0
> txqueuelen:1000
> RX
bytes:626
> (626.0 B) TX bytes:10727 (10.7
KB)
>
> Requires no special setup.
>
> However on a FreeBSD machine I need to
do this:
>
> USBDEV=$(shell dmesg | grep
'^ugen.*LCD' | sed -E
> 's/^ugen([0-9]+\.[0-9]+).*/\1/')
> # target to make the device show up on
freebsd.
> config-freebsd:
> usbconfig -d
> $(USBDEV) set_config 1
> sleep 5
> ifconfig ue0
inet
> 169.254.99.129/24 up
>
> Basically I need to grep dmesg for
"ugen" and the string
> "LCD", then I
> need to run:
> usbconfig -d 3.3 set_config
1 # (3.3 comes from
> dmesg)
> then..
> ifconfig ue0 inet
169.254.99.129/24 up
>
> Any idea why Linux can do this all
automagically but FreeBSD
> needs
> manual help?
>
>
> I even tried putting some stuff into
devd.conf, however devd
> doesn't
> seem to the right thing if the device
is plugged in at boot
> time. This
> is because devd only seems to know
when a device is plugged
> in, however
> it doesn't trigger events when the
device has been present
> since boot.
>
> Any tips on this? We can get
around this with some
> custom rc scripts,
> but I was just wondering if FreeBSD
could make it more plug
> and play.
>
> thanks,
> -Alfred
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