On Tue, 31 Jul 2012, Oliver Neukum wrote: > On Monday 30 July 2012 17:03:27 Alan Stern wrote: > > On Mon, 30 Jul 2012, Sarah Sharp wrote: > > > I'm not even sure that RESET_MORPHS is the right thing to look at here. > > It's possible for a device to retain important settings across a reset > > but lose them when power is removed. > > True. So an additional quirk? QUIRK_FIRMWARE_VOLATILE? To be consistent we should call it QUIRK_POWEROFF_MORPHS. But how is this quirk going to get set? Static entries in the quirks table? Dynamically by firmware loaders? > > > 2. If the device is internal and suspended, power off the port if all > > > the following are true: > > > > > > a) all interface drivers have supports_power_off set, or no > > > interface drivers are bound and usbfs has not claimed the > > > device. > > > b) remote wakeup is disabled > > > c) USB_QUIRK_RESET_MORPHS is not set > > > > > > - If userspace wants a port to be powered off, and one of the interface > > > drivers doesn't set supports_power_off or the driver enables remote > > > wakeup, then userspace will need to unbind or unload the driver. > > > > Like other people, I'm dubious about these conditions. > > Can you propose other conditions? I don't know. I can't think of anything more, but there's a nagging feeling that if we use these then something will go wrong. How about if we start with only the first policy rule: Ports that can never have anything plugged in should be shut down automatically. Initially, everything else can be left up to userspace. Then we can experiment with adding other policies to the kernel. 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
