On Tue, 31 Jul 2012, Bjørn Mork wrote: > Alan Stern <st...@rowland.harvard.edu> writes: > > On Mon, 30 Jul 2012, Sarah Sharp wrote: > > > >> - I'm not sure if it's true that all devices that need firmware will > >> have USB_QUIRK_RESET_MORPHS set. Alan, Oliver? > > > > Probably not, and in any case the situation is more complex than it > > first appears. (In fact, I wonder whether we really need that quirk > > flag at all -- as far as I can tell it's not doing anybody any good.) > > usb_modeswitch use it to prevent usb-storage from resetting the device > on errors. Some 3G modems expose a storage interface (SD card reader > and/or embedded driver CD) even after switching to modem mode. You do > not want them to switch back from modem mode on every usb-storage > problem, especially as you may assume the device firmware is buggy. Some > devices would probably end up in a continuous reset loop without this > quirk.
Okay. Guess I should have known that. > IMHO that should have been the default for any composite device, but > whatever.. I don't think it's very nice of usb-storage to reset the > device if there are drivers bound to other functions. That's why we have pre_reset and post_reset callbacks. The alternative is to lose access to all the mounted filesystems on the mass-storage device, which isn't very nice either. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
