From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Karl O. Pinc" <kop@meme.com>
Date: Thu, 20 Nov 2008 14:37:21 +0000
Subject: Re: WAIT_FOR_SYSFS error, Is my udev rule wrong?
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List-Id: <linux-hotplug.vger.kernel.org>
References: <1227160064l.14872l.4l@mofo>
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To: linux-hotplug@vger.kernel.org


On 11/20/2008 12:30:19 AM, Kay Sievers wrote:
> On Thu, Nov 20, 2008 at 06:47, Karl O. Pinc <kop@meme.com> wrote:
> > I've written a udev rule and am looking
> > for comment by those with more experience
> > to see if there are improvements to be made.
> > KERNEL="ttyUSB0", ACTION="add", WAIT_FOR_SYSFS="subsystem/ttyUSB0"
> 

> The device you get the event for has only a single attribute, called
> "dev" and there is never a need to wait for that. WAIT_FOR* is to work
> around (in most cases broken and should be fixed) sysfs timing issues
> in the kernel. Seems, there is nothing in your event where that would
> be needed.
> 
> What are you trying to wait for?

I am trying to wait long enough that at startup the ldc4linux
daemon does not log the error:

Nov 19 16:15:00 mustard LCD4Linux[15799]: Pertelian: open(/dev/ttyUSB0)
failed: No such file or directory

It seems to work anyway, but I interpret the error to mean that
something in udev has not finished by the time the daemon
starts.  I don't get the error if I start lcd4linux
manually after plugging in the lcd panel.

Thanks for the help.

Karl <kop@meme.com>
Free Software:  "You don't pay back, you pay forward."
                  -- Robert A. Heinlein