On Fri, Nov 19, 2010 at 11:50:43PM +0300, Vladislav Bolkhovitin wrote: > Dmitry Torokhov, on 11/19/2010 11:22 PM wrote: > >> None of the SCST objects are Linux devices. None of them has entries in > >> /dev, none of them needs to send any events to udev and none of them > >> sends or receives data from DMA, hence has any DMA parameters or > >> restrictions. So, how can them fit into the driver/bus/device model you > >> are enforcing? > > > > Note that the entities in /sys/devices/... tree and not necessarily > > physical devices bit rather interface abstractionss. Consider, for > > example, /sys/class/input/*. None of the "devices" there talk directly > > to hardware, do DMA or other things. Some of them don't even talk to > > usrespace directly but rather through additional interfaces (evdev. > > mousedev, ect). Still they are represented there and even have suspend > > and resume methods (because even for logical devices it makes sense to > > save and restore some state). This is correct. > SCST devices are not even logical devices. As I wrote, "devices" word is > misleading. SCST devices are converse of what Linux means under this > word. SCST devices are like NFS exports: a place where those events > generated and those requests received. No, that's fine. > Think of SCST device as if it sits on the opposite side of the PCI bus > of the corresponding SCSI device Linux sees in /sys/class and /sys/bus. Again, that's fine, look at usb gadgets, it's the same thing. > So, if we need Linux devices for SCST devices, we create them using > scst_local driver. And then, of course, all them have their place in > /sys/class/ and /sys/bus. No, just /sys/bus/ which will cause them to become part of the big device tree in /sys/devices/ Again, use this interface, it is what it is there for, to not use it is just wrong. good luck, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
