On Tue, 12 Mar 2013, Martin Mokrejs wrote: > Hi Greg, > > Greg KH wrote: > > On Tue, Mar 12, 2013 at 11:45:39AM +0100, Martin Mokrejs wrote: > >> Hi, > >> while testing how my computer behaves with USB disabled I see this line still > >> in dmesg output: > >> > >> Initializing USB Mass Storage driver... > > > > Did you build the driver into the kernel? Or is it being automatically > > loaded by something? > > No, it is statically included in the kernel, like ehci and xhci is. For testing > I wanted to disable all USB stuff. And you succeeded. > >> Is there any driver able to use it under 'nousb' situation at all? Shouldn't it > >> be prevented from loading as well? This was tested on 3.9-rc1. > > > > If userspace loads a driver, there's nothing the kernel can do about it > > :) > > > > Is there a problem of it being loaded? Just don't build the module at > > all if you don't want it. > > No, I just wondered why 'nousb' disables on the runtime ehci/xhci (also included > statically in the kernbel binary) while not other USB-related modules. Because the other USB-related modules don't need to be disabled. > Maybe it > was thought that no downstream modules will load because of unmet dependencies > ... but looks usb-storage can load fine without them. "Load" is the wrong word. Modules that are built into the kernel, not built separately, get loaded along with the rest of the kernel. You really mean that usb-storage can initialize fine without them (see the line you quoted from the dmesg log). It can. But once it is initialized, it doesn't do anything more. > The question is whether there is any module at all capable of using usb-storage > while ehci/uhci/xhci are NOT available. This question is not expressed clearly. If ehci/uhci/xhci/etc. are not available then the kernel cannot use any USB controllers. Consequently it cannot detect or communicate with any USB devices. Therefore, although drivers like usb-storage or usbhid may be initialized and ready, there is no work for them to do. > I don't have that much a problem with the behavior as it is now. ;) Just FYI > that it was a bit unexpected to see it loaded at all. It wasn't loaded -- it was built into the kernel from the beginning. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
