cangeing device connection error

cybmole · 04-05-2014, 02:02 AM

I need to run more tests to definitively prove this but I think there is a sequence which leads to a calibre crash
1. connect, then eject device 1 ( Kobo aura HD in my case)
2. now connect a device which is in standby ( KF HDX in my case)

the action of plugging in the usb cable sort of wakes the 2nd device but calibre then gives a device connect error and in details it gives a long spiel about device wanting to go to standby ( i.e. it seems to think it is dealing still with device 1 ... )

3. if I continue trying to use calibre anyway, as it is showing a "device", I soon get to "calibre has stopped working" windows error & program closes.

it is not a problem per se with the KF, I connected that in a standby state this morning and all was well, so the device error is more to do with swapping devices while calibre is running.

anyone have any similar experiences or insights

kovidgoyal · 04-05-2014, 02:14 AM

Wake up your device before plugging it in and you will be fine. I'm guessing the KF's firmware sends some invalid data to the WPD subsytem when it is in standby and plugged in.

cybmole · 04-05-2014, 02:40 AM

Quote:

Originally Posted by kovidgoyal

Wake up your device before plugging it in and you will be fine. I'm guessing the KF's firmware sends some invalid data to the WPD subsytem when it is in standby and plugged in.

1. I am sure that is correct, but...
2. I tested today by bringing PC out of standby then connecting an "asleep" KF and all was good.

so there's another factor at play

let's see if I can reproduce what I did yesterday....
I eject KF, connect Kobo, eject that from within calibre, unplugged it.. now plugging KF back in ( which is back in standby) and...

no error !

SO much for that exact theory. I will grab the exact error messages if the problem ever returns- it could be that KF has to have been in standby for a long time, not just for a couple of minutes in order for this to show up

(PS I always use the same USB cable, which is perma-connected at PC end, so I doubt that it is a cable issue - but it could be something really silly like not pushing the USB plug all the way in at the KF end, I suppose )

04-05-2014, 02:02 AM	#1
cybmole Wizard Posts: 3,720 Karma: 1759970 Join Date: Sep 2010 Device: none	cangeing device connection error I need to run more tests to definitively prove this but I think there is a sequence which leads to a calibre crash 1. connect, then eject device 1 ( Kobo aura HD in my case) 2. now connect a device which is in standby ( KF HDX in my case) the action of plugging in the usb cable sort of wakes the 2nd device but calibre then gives a device connect error and in details it gives a long spiel about device wanting to go to standby ( i.e. it seems to think it is dealing still with device 1 ... ) 3. if I continue trying to use calibre anyway, as it is showing a "device", I soon get to "calibre has stopped working" windows error & program closes. it is not a problem per se with the KF, I connected that in a standby state this morning and all was well, so the device error is more to do with swapping devices while calibre is running. anyone have any similar experiences or insights

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04-05-2014, 02:14 AM	#2
kovidgoyal creator of calibre Posts: 45,365 Karma: 27230406 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Wake up your device before plugging it in and you will be fine. I'm guessing the KF's firmware sends some invalid data to the WPD subsytem when it is in standby and plugged in.