Hi David, > The HIDP specs define an idle-timeout which automatically disconnects a > device. This has always been implemented in the HIDP layer and forced a > synchronous shutdown of the hidp-scheduler. This works just fine, but > lacks a forced disconnect on the underlying l2cap channels. This has been > broken since: > > commit 5205185d461d5902325e457ca80bd421127b7308 > Author: David Herrmann <dh.herrmann@xxxxxxxxx> > Date: Sat Apr 6 20:28:47 2013 +0200 > > Bluetooth: hidp: remove old session-management > > The old session-management always forced an l2cap error on the ctrl/intr > channels when shutting down. The new session-management skips this, as we > don't want to enforce channel policy on the caller. In other words, if > user-space removes an HIDP device, the underlying channels (which are > *owned* and *referenced* by user-space) are still left active. User-space > needs to call shutdown(2) or close(2) to release them. > > Unfortunately, this does not work with idle-timeouts. There is no way to > signal user-space that the HIDP layer has been stopped. The API simply > does not support any event-passing except for poll(2). Hence, we restore > old behavior and force EUNATCH on the sockets if the HIDP layer is > disconnected due to idle-timeouts (behavior of explicit disconnects > remains unmodified). User-space can still call > > getsockopt(..., SO_ERROR, ...) > > ..to retrieve the EUNATCH error and clear sk_err. Hence, the channels can > still be re-used (which nobody does so far, though). Therefore, the API > still supports the new behavior, but with this patch it's also compatible > to the old implicit channel shutdown. > > Cc: <stable@xxxxxxxxxxxxxxx> # 3.10+ > Reported-by: Mark Haun <haunma@xxxxxxxxx> > Reported-by: Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx> > Signed-off-by: David Herrmann <dh.herrmann@xxxxxxxxx> > --- > Hi Mark & Luiz > > Can you give this a spin? This should fix the reported issues! I like the > implementation much more than calling shutdown(2) implicitly in the kernel. > With sk_err we avoid enforcing a behavior and let user-space deal with it. > > Btw., this needs back-porting to >=3.10 (which introduced the new session > management). > > Thanks for the report! > David > > net/bluetooth/hidp/core.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) patch has been applied to bluetooth-next tree. Regards Marcel -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
