Hotplug and USB device removal

Hotplug and USB device removal

[Stephen Williams]

I'm building a USB flash programmer with an EZ-USB chip. So far, it
works fine, I'm able to plug in the device and have the hotplug
usb.agent script notice it and start my demon. All this demon does
is set permissions for the usbdevfs file and create a link in /var/run
to point to the device. Thusly, the application can access the device
as a normal user.

However, I would also like to use the hotplug system to notice the
removal of the device and *remove* my symbolic link. The scripts
currently do not support USB remove. It looks like the kernel sends
all the necessary messages, but the script just needs updating. Is
anyone working on this?

Also, as you guessed, I have a program that loads the ez-usb device
from user mode. It won't be much effort for me to polish up and
make it available to the world (especially since it supports sdcc
output) as a generic ez-usb loader, but there must be millions of
them out there:-)

-- 
Steve Williams                "The woods are lovely, dark and deep.
steve@icarus.com              But I have promises to keep,
steve@picturel.com            and lines to code before I sleep,
http://www.picturel.com       And lines to code before I sleep."



_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
http://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: Hotplug and USB device removal

[Brad Hards]

Stephen Williams wrote:
> Also, as you guessed, I have a program that loads the ez-usb device
> from user mode. It won't be much effort for me to polish up and
> make it available to the world (especially since it supports sdcc
> output) as a generic ez-usb loader, but there must be millions of
> them out there:-)
I would be keen to see this loader work with the ezusb_load_0-3.tar.gz module
that Adam Richter put together (ftp://ftp.yggdrasil.com/private/adam/ezusb/).
Ideally, the loader would be generalized to handle a range of different
formats (automatically, if possible). I had planned to do some work in this
area (sdcc toolchain, and support libs for EZUSB FX2), but I also have an
original anchorchips EZUSB board to do some testing (and a port of the ezload
code from the BSD community).

I still don't support removing the various firmware codes from the kernel
without better reasons that have been presented to date, but I do support
being _able_ to do it from user speace.

Brad

_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
http://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: Hotplug and USB device removal

[Stephen Williams]

Stephen Williams wrote:
> Also, as you guessed, I have a program that loads the ez-usb device
> from user mode.


bhards@bigpond.net.au said:
> Ideally, the loader would be generalized to handle a range of
> different formats (automatically, if possible).


Well, My loader supports intel hex files that sdcc generates, and it
also sets the permisions and creates a soft link if so requested. I've
abstracted the loader a bit more so that it is easier to add support
for other formats, i.e. S-Records and Adam's hacked format.

With this program, my hotplug script looks like this:

  !/bin/sh

  # This script is the part of the server that goes into the hotplug
  # directory. It takes the parameters of the policy agent and makes
  # calls to the gflashd server.

  case "$PRODUCT" in

  547/2235/*)
    exec /usr/sbin/gflashd -I /usr/share/gflash/aa55.ihx ;;

  12c5/*/*)
    exec /usr/sbin/gflashd -m 0666 -L/var/run/gflash.lnk ;;
  esac

(This handles the renumeration by detecting the Cypress chip. I haven't
programmed the eeprom on this device yet.)

My application, then, can just look for the /var/run/gflash.lnk
symbolic link to show up, and that is the device appearing and ready.

The problem here is that the link persists even when the device
is disconnected. The usb.agent script does not pass on remove events
to interested scripts.
-- 
Steve Williams                "The woods are lovely, dark and deep.
steve@icarus.com              But I have promises to keep,
steve@picturel.com            and lines to code before I sleep,
http://www.picturel.com       And lines to code before I sleep."



_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
http://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: Hotplug and USB device removal

[Brad Hards]

Stephen Williams wrote:
> The problem here is that the link persists even when the device
> is disconnected. The usb.agent script does not pass on remove events
> to interested scripts.
I just looked at the call_policy() code in usb.c, and it looks like the
"remove" event is supported by the code. What are you seeing in the debug logs
(assuming that you have debugging turned on)? In particular, are you seeing
"In_interrupt" messsages in your logs?

Brad

_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
http://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: Hotplug and USB device removal

[Brad Hards]

Stephen Williams wrote:
> 
> Stephen Williams wrote:
> > Also, as you guessed, I have a program that loads the ez-usb device
> > from user mode.
> 
> bhards@bigpond.net.au said:
> > Ideally, the loader would be generalized to handle a range of
> > different formats (automatically, if possible).
> 
> Well, My loader supports intel hex files that sdcc generates, and it
> also sets the permisions and creates a soft link if so requested. I've
> abstracted the loader a bit more so that it is easier to add support
> for other formats, i.e. S-Records and Adam's hacked format.
The Keil toolchain eventually ends up with Intel hex as well. I'd be keen to
see this made available, and made to support the firmware format used by Adam.
I'm a bit busy at the moment, although I do need a tool for the EZUSB FX2
chipset, so I'll have to find some time. I remember you said that you needed
to clean it up first - I'd encourage you to do so. It'd be good to somehow
harmonise on a single tool for all these ezusb firmware applications.

Brad

_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
http://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: Hotplug and USB device removal

[Stephen Williams]

bhards@bigpond.net.au said:
> The Keil toolchain eventually ends up with Intel hex as well.

It can also make S-Records, if I recall correctly. Anyhow, it should
work with what I have.

Adam's format includes not just the bytes and addresses, but the 0xa0
of the commands as well. I suspect he didn't quite understand the
workings of the ez-usb chip (he said as much on the linux-usb-devel
mailing list) so may have thought that it was information.


bhards@bigpond.net.au said:
> I remember you said that you needed to clean it up first

Pretty much done. Here's a snapshot:

    <ftp://icarus.com/pub/steve/gflashd.tgz>

At the moment it is part of my gflash product, but if it finds a different
home I'll maintain it wherever it lives.
-- 
Steve Williams                "The woods are lovely, dark and deep.
steve@icarus.com              But I have promises to keep,
steve@picturel.com            and lines to code before I sleep,
http://www.picturel.com       And lines to code before I sleep."



_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
http://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: Hotplug and USB device removal

[Stephen Williams]

bhards@bigpond.net.au said:
> I just looked at the call_policy() code in usb.c, and it looks like
> the "remove" event is supported by the code. What are you seeing in
> the debug logs (assuming that you have debugging turned on)?


May 19 07:14:24 beeker /sbin/hotplug: invoke /etc/hotplug/usb.agent ()
May 19 07:14:24 beeker /etc/hotplug/usb.agent: USB remove event not supported

It is apparently just the usb.agent script that lacks the necessary
support for USB remove events.  Unless my copy is out of date already.
-- 
Steve Williams                "The woods are lovely, dark and deep.
steve@icarus.com              But I have promises to keep,
steve@picturel.com            and lines to code before I sleep,
http://www.picturel.com       And lines to code before I sleep."



_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
http://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: Hotplug and USB device removal

[David Brownell]

> However, I would also like to use the hotplug system to notice the
> removal of the device and *remove* my symbolic link. The scripts
> currently do not support USB remove. It looks like the kernel sends
> all the necessary messages, but the script just needs updating. Is
> anyone working on this?

Not unless you're volunteering ... :)


> Also, as you guessed, I have a program that loads the ez-usb device
> from user mode. It won't be much effort for me to polish up and
> make it available to the world (especially since it supports sdcc
> output) as a generic ez-usb loader, but there must be millions of
> them out there:-)

Well, I think that one which handles both the FX and FX2, and
which is generically integrated with the USB hotplugging, would be
far more interesting than the other millions-less-one !

(The FX2 download procedure seems to be the same as for
the FX, but the register used to control reset after downloading
firmware has a different address.)

- Dave




_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
http://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: Hotplug and USB device removal

[Greg KH]

On Sat, May 19, 2001 at 07:09:48AM -0700, Stephen Williams wrote:
> 
> Adam's format includes not just the bytes and addresses, but the 0xa0
> of the commands as well. I suspect he didn't quite understand the
> workings of the ez-usb chip (he said as much on the linux-usb-devel
> mailing list) so may have thought that it was information.

The 0xa0 is needed for devices like the WhiteHEAT that first loads a
special loader into the EZUSB device, and then loads extra firmware.  It
uses two different commands to get this to work.  See the current
drivers/usb/serial/whiteheat.c file to see how this works, and why it is
necessary.

There is also a script in the drivers/usb/serial directory that takes
Intel hex records and converts them to the format used by the current
drivers (a .h file full of records.)  That script can be modified to do
some other kind of output if you wish.

thanks,

greg k-h

_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
http://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: Hotplug and USB device removal

[Stephen Williams]

> [...] It looks like the kernel sends
> all the necessary messages, but the script just needs updating. Is
> anyone working on this?

david-b@pacbell.net said:
> Not unless you're volunteering ... :) 

As long as I'm not stepping on toes, this is pertinent to my day job;
so sure I'm volunteering. I just want to make sure that it can work,
and that I'm not going to conflict with the work of others.


david-b@pacbell.net said:
> Well, I think that one which handles both the FX and FX2, and which is
> generically integrated with the USB hotplugging, would be far more
> interesting than the other millions-less-one !

The CPUCS at 0x7f92 is it for the FX. If the FX2 works differently,
then some configuration is needed. You can't autodetect based on device
id as they can (and should be) set by a 0xb4 or 0xb6 load from the
EEPROM.

However, it's pretty trivial to have a ``-t fx'' and ``-t fx2''
switch that the hotplug scripts can invoke. I'd be happy to cooperate
on this. Someone with an FX2 board can send me patches, that's fine.

I think it is better to use standard ihex and srecord files wherever
possible, as they can be generated and manipulated by commonly available
tools, free and commercial.
-- 
Steve Williams                "The woods are lovely, dark and deep.
steve@icarus.com              But I have promises to keep,
steve@picturel.com            and lines to code before I sleep,
http://www.picturel.com       And lines to code before I sleep."



_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
http://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel