Am Montag, 14. Dezember 2009 21:19:38 schrieb Alan Stern: > On Mon, 14 Dec 2009, Oliver Neukum wrote: > > > Hi Josua, Alan, > > > > as we discussed earlier devices which need to be switched must > > not be reset. Currently I think only the storage driver is affected. > > Ideally we would not put all those devices into the quirks list. > > I'd prefer the user space tools making the switch to tell the kernel > > that the new device is quirky. > > What kind of API for that would you prefer? > > Note that users can turn the persist_enabled flag back on through > sysfs. Yes, the user can do that. The kernel is supposed to provide safe defaults. Protecting the user from himself is not its job. > Also note that other drivers will reset a device to recover from errors > (usbhid for example). I haven't heard of a switched device with an HID interface. > Do we really have to do this? How often will it be a problem? We do have a problem here. > usb-storage's class-specific reset mechanism almost never works, But a) a generic reset will never work b) the other interfaces may still work > probably because Windows doesn't use it. So what does Windows do when > such a device gets an error in its mass-storage interface? I don't know. I suspect Windows switches modes in kernel space. Regards Oliver -- 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
