From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bernd Porr Date: Wed, 03 Dec 2008 11:13:32 +0000 Subject: Re: usb coldplug problem Message-Id: <493669DC.9070907@f2s.com> List-Id: References: <403A9FAC.2010904@free.fr> In-Reply-To: <403A9FAC.2010904@free.fr> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org I totally take Greg's point that the firmware load should be via a firmware request from the driver which then in turn triggers the firmware helper in userspace. When I checked that last time (about a year ago) this was too buggy and I stuck with the comedi firmware upload which has been running for about 4 years without probs. Might be a good time to use the firmware helper. But in comedi it is so that the command "comedi_config" associates a driver with a device. This works fine with hotplug. I plug in my usbdux, this triggers a udev event and then a udev rule can decide which /dev/comedi? is actaully taking care of the box. If you want to question that mechanism then comedi itself has to be rewritten. And I'm sure that nobody here in comedi-land would like to do that. It just works too good. > Why cannot be the /proc interface be used. Can you explain that a bit more. Thanks! /Bernd Sujit Karataparambil wrote: > We need to call the rule in the kernel context as 'greg' was saying. > > Seems to be the correct way to be the firmware upload via USB. > > On 12/3/08, Kay Sievers wrote: >> On Wed, Dec 3, 2008 at 09:40, Bernd Porr wrote: >> >>>> Yes it will as the startup scripts already know how to handle coldplug >>>> firmware events. >>> To give the "magic" a name: you mean udev adm trigger? Or a nice script >>> which writes "add" to all "uvents"? This is exactly what doesn't work. There >>> are absolutely no udev events generated for comedi during boot. I've checked >>> that now thoroughly and I think there's something wrong. What could that be? >> How does the "device" look like in sysfs, where you want to hook into >> with the userspace setup? >> >> Kay >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > -- www: http://www.berndporr.me.uk/ http://www.linux-usb-daq.co.uk/ http://www.myfriendhelen.org.uk/ Mobile: +44 (0)7840 340069 Work: +44 (0)141 330 5237 University of Glasgow Department of Electronics & Electrical Engineering 72 Oakfield Avenue (Rankine Building for deliveries) Glasgow, G12 8LT