Am 19.01.2016 um 10:10 schrieb Jacek Anaszewski: > Hi Heiner, > > On 01/18/2016 09:52 PM, Heiner Kallweit wrote: > >>> Yes, this seems to be the best solution. Driver should set this flag >>> before calling led_classdev_unregister. If the flag is set the -ENODEV >>> error will not be reported. It could be named LED_HW_ABSENT for >>> instance. Feel free to propose other ideas. >>> >> Setting such a flag from the driver might cause significant effort in different layers. >> When we talk about thingm as an example, it uses the hid subsystem with the usbhid low level driver. >> We would need a callback in the usbhid driver (to be notified when the device is unplugged) >> and a way to propagate this event to the hid core. > >> Maybe simpler: We could ignore ENODEV errors if a function is called from led_classdev_unregister. >> This way we wouldn't have to touch drivers. I think of something like this: > > Ignoring -ENODEV errors for all devices would filter out also valid > error cases and hinder debugging. > > How about adding a flag LED_HW_PLUGGABLE in addition to > LED_UNREGISTERING, and make the pluggable LED class drivers having set > it all the time. The -ENODEV error would be reported only > if !(LED_UNREGISTERING && LED_HW_PLUGGABLE). > Sounds good, I'll send a patch including the additional LED_HW_PLUGGABLE flag. The patch may apply cleanly only after applying a comment fix I sent on Jan 10th. (led: core: fix misleading comment after workqueue removal from drivers) Regards, Heiner -- To unsubscribe from this list: send the line "unsubscribe linux-leds" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
