Messages in this thread | | | Subject | Re: [PATCH 1/2] cdc-acm: do not reset notification buffer index upon urb unlinking | From | Oliver Neukum <> | Date | Thu, 04 Oct 2018 15:32:41 +0200 |
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On Sa, 2018-09-22 at 22:11 +0200, Tobias Herzog wrote: > Resetting the write index of the notification buffer on urb unlink (e.g. > closing a cdc-acm device from userspace) may lead to wrong interpretation > of further received notifications, in case the index is not 0 when urb > unlink happens (i.e. when parts of a notification already have been > transferred). On the device side there is no "reset" of the notification > transimission and thus we would get out of sync with the device.
Hi,
you are right, when you are describing the problem. The fix seems to me to fix a part, albeit a large part of the issue. As far as I can tell, the transfer could be partially succesful, meaning that the driver loses a part in the middle of the notification.
Regards Oliver
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