From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kay Sievers Date: Sat, 14 Jan 2006 13:27:14 +0000 Subject: Re: cold plugging Message-Id: <20060114132714.GB12273@vrfy.org> List-Id: References: <200601131415.30207.treeve@scarlet.be> In-Reply-To: <200601131415.30207.treeve@scarlet.be> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org On Sat, Jan 14, 2006 at 06:10:48PM +0500, Alexander E. Patrakov wrote: > Kay Sievers wrote: > >On Sat, Jan 14, 2006 at 10:00:29AM +0500, Alexander E. Patrakov wrote: > >>Greg KH wrote: > >> > >>>Why does USB take longer for you? What is taking such a long time? > >>> > >>The /dev/bus/usb/... node for my Mustek Plug-N-Scan 1200 UB Plus scanner. > > > >It's the simplest way to wait for all events. Depending how you handle > >dependencies/checkoints on bootup, it may be sudfficient if all localfs > >devices have appeared and you can let the other events finish > >asynchronously. > > > > > Thanks, but you probably missed the point. Your loop does NOT wait for > all events. I think that in my case the following happens: > > 1) The script creates an empty /dev/.udev/queue directory > 2) The script causes the kernel to emit uevents > 3) udevd gets those uevents, and reacts upon them. This reaction > involves, among other things, making device nodes and calling > /sbin/modprobe to load new drivers. > 4) Those drivers are bound to devices by the kernel, this produces new > uevents, go to (3). > 5) When the internal queue of udevd becomes empty, it removes the > /dev/.udev/queue directory and the loop exits. > > The problem is that some modules take longer than 0.1s to detect their > hardware, so there is a period of time longer than 0.1s with the empty > udevd queue, after which new uevents arrive. Which modprobe for which module is it, that returns before events for the devices are generated? Kay ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://ads.osdn.com/?ad_idv37&alloc_id865&op=click _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel