From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Knecht Date: Fri, 19 Jan 2001 00:22:49 +0000 Subject: RE: netdevice problem - 1394 SPB-2 Drives Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org Hi, First, I'm not the guy to make any decisions about how this might get done in the 1394 driver stack. I'm a hardware guy and system oriented. However, that said, the 1394 usage model is more similar to USB, in general, than it is to SCSI. There are lots of 1394 devices. They serve lots of purposes. And hot plugging is a basic part of the way 1394 works, at both the hardware and software levels. Additionally, there are 1394 bridges coming which will link together many 1394 buses, and there are going to be both local and distant discovery issues involved when devices are added and removed. I presume that _eventually_ we'll want to be able to extend the hot plugging concepts to find 1394 disk drives that are located a couple of miles away across some 1394b interface. But that's in the future. So, I think part of the issue here is that the 1394 stack is going to have a fairly low level part that is handling the hardware part of notifying the system that something has happened. Above that the 1394 stack will probably need to let the hot plugging system know about certain device changes, but possibly not about all devices. Do you see this software being responsible when I plug in 1394 printers, cameras, speakers, home theatre equipment, as well as disk drives? I'm not clear... Thanks for the opportunity to wave the flag for 1394! Mark -----Original Message----- From: Oliver Neukum [mailto:Oliver.Neukum@lrz.uni-muenchen.de] Sent: Thursday, January 18, 2001 3:18 PM To: David Brownell; Mark Knecht; linux-hotplug-devel@lists.sourceforge.net Subject: Re: netdevice problem - 1394 SPB-2 Drives On Thursday 18 January 2001 22:47, David Brownell wrote: > > How do you guys seeing 1394 disk drives fitting into the hot-plug mix? > > Right on top of basic 1394 hotplug support! > > The hotplug bus support for PCI and USB is pretty similar ... how well > do these map to the ieee1394 subsystem? That's not the issue in this case. SCSI is the problem. I've looked at that driver. It needs to deal with device addition/removal. As there are a lot of device on a firewire bus, it probably can't use the pseudo host controller hack. And shouldn't - it's a hack, which is unfortunately necessary for usb. At present hotplugging in this driver sucks and will continue to do so until the scsi subsystem is extended. Even then for configuration there's a need to further support. The raw news about a device is of little use. You need the information about partitions and other things. Regards Oliver _______________________________________________ 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