On Fri, Jul 27, 2012 at 11:25:46AM -0700, Greg KH wrote: > On Fri, Jul 27, 2012 at 02:12:12PM -0400, Matthew Wilcox wrote: > > I don't see a problem here, but I'm no expert at sysfs / character devices. > > Alan, Greg, anyone else see any problems with how this character device is > > created / destroyed? > > Yes, see below:
Thanks! > > > + device_create(nvme_char_cl, NULL, MKDEV(nvme_char_major, dev->instance), > > > + NULL, "nvme%d", dev->instance); > > You just created a device at the "root" of sysfs, which is wrong, > especially when you do have a parent device here. Please use it. OK, that makes sense; this device should be the child of the pci_dev that it belongs to. > Also, why are you creating your own class? Can't this just be a misc > device? And if you want to create your own class, please don't, use a > bus, as that is what is really happening here, right? We are trying to > move away from using 'struct class' wherever possible (one of these days > we'll just remove it...) What we're trying to achieve here is to create one character device per NVMe controller that gets plugged in. Each NVMe controller is-a PCI function. The reason we're trying to do this is so that we can send commands to the NVMe controller, even when there is no storage present (eg a drive is shipped from the factory with no configured storage). So we have no particular desire to create a new struct class, or struct bus. If we can create a misc device per PCIe function that's bound to our driver, that's great! Can you recommend a driver that does this already? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
