ttyS0 access

[lawson_whitney at juno.com]

| Until last week my wine runs a Microcontroler Programmer under serial
| port very well,
| But in this week have problems to work wine for serial ports on my new
| Mandrake 8.1.
|
| Well, in Mdk 8.1 there is no ttyS0 devices but links to /dev/tts/0 and
| /dev/tts/1

I wondered when a distro would use devfs.  devfs is a kernel option for
the 2.4.x kernels, you can disable it at boot time if you like, but I
have never done so and have lost track of how.  This mail comes to you
by Wine over /dev/tts/3, kernel 2.4.10 with devfs and devfsd, so it can
be done.  First, make sure devfsd is running:

ps xa|grep -v grep|grep devfsd

I reckon it is:  it is what makes the symbolic links to /dev/tts/.

Now have a look at /etc/devfsd.conf ... this is what I did to the
default devfsd.conf, probably I had a reason:

--- devfsd.conf	Mon Jul  3 16:46:32 2000
+++ /etc/devfsd.conf	Sun Aug 12 20:55:18 2001
@@ -27,6 +27,9 @@

 #
 # Uncomment this if you want permissions to be saved and restored
-#REGISTER	.*		COPY	/dev-state/$devname $devpath
-#CHANGE		.*		COPY	$devpath /dev-state/$devname
-#CREATE		.*		COPY	$devpath /dev-state/$devname
+REGISTER	tts/.*		COPY	/dev-state/$devname $devpath
+CHANGE		tts/.*		COPY	$devpath /dev-state/$devname
+CREATE		tts/.*		COPY	$devpath /dev-state/$devname
+REGISTER	vc/.*		COPY	/dev-state/$devname $devpath
+CHANGE		vc/.*		COPY	$devpath /dev-state/$devname
+CREATE		vc/.*		COPY	$devpath /dev-state/$devname

In case you are not used to reading unified diffs, this is what I end up
with at the end of devfsd.conf:

#
# Uncomment this if you want permissions to be saved and restored
REGISTER	tts/.*		COPY	/dev-state/$devname $devpath
CHANGE		tts/.*		COPY	$devpath /dev-state/$devname
CREATE		tts/.*		COPY	$devpath /dev-state/$devname
REGISTER	vc/.*		COPY	/dev-state/$devname $devpath
CHANGE		vc/.*		COPY	$devpath /dev-state/$devname
CREATE		vc/.*		COPY	$devpath /dev-state/$devname
|
| I realy don't remember how was until last week, but I think about users
| and perms to devices.
| I try to chmod a+rw for /dev/tts/0 and tts/1 but does not work.

Now give devfsd a SIGHUP and try your chmod again, or maybe one a little
less sloppy.  Do you really want just _anybody_ to use a comm port?

killall -HUP devfsd
|
| In the bash where I call the wine messages apears like that:
| fixme:comm:EnableCommNotification16 no handle for cid = ffffffff!
| ...
| fixme:comm:CloseComm16 no cid=-1 found!
|
All this just says the open failed, but the stupid app is trying to use
it anyway.
|
| 	Please, if anyone can aid me about access serial ports reply
| me, cause I need it to my job. Tanx all.
|
| 	Antonio Augusto Todo Bom Neto
|
| PS: Very thanks to Bernhard Rosenkränzer for the Daily rpm build in the
| site www.linux-easy.com.
|
You can find more doco in man devfsd, maybe /usr/share/doc/devfsd*, and

http://www.atnf.csiro.au/~rgooch/linux/docs/devfs.html
http://www.atnf.csiro.au/~rgooch/linux/

If you installed kernel source,
<linux>/Documentation/filesystems/devfs/

Lawson
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