Hi Andre, On Fri, Mar 02, 2012, Andre Guedes wrote: > > On Thu, Mar 01, 2012, Andre Guedes wrote: > >> We are not supposed to force DISCOVERY_STOPPED in inquiry_cache_flush > >> because we may break the discovery state machine. For instance, > >> during interleaved discovery, when we are about to start inquiry, > >> the state machine forcibly goes to DISCOVERY_STOPPED while it > >> should stay in DISCOVERY_FINDING state. > >> > >> This problem results in unexpected behaviors such as sending two > >> mgmt_discovering events to userspace (when only one event is > >> expected) and Stop Discovery failures. > >> > >> Signed-off-by: Andre Guedes <andre.guedes@xxxxxxxxxxxxx> > >> --- > >> net/bluetooth/hci_core.c | 1 - > >> 1 file changed, 1 deletion(-) > >> > >> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c > >> index d3ddc0b..661d65f 100644 > >> --- a/net/bluetooth/hci_core.c > >> +++ b/net/bluetooth/hci_core.c > >> @@ -413,7 +413,6 @@ static void inquiry_cache_flush(struct hci_dev *hdev) > >> > >> INIT_LIST_HEAD(&cache->unknown); > >> INIT_LIST_HEAD(&cache->resolve); > >> - cache->state = DISCOVERY_STOPPED; > >> } > > > > Nack. > > > > The reason why this was there is hci_dev_do_close() and hci_dev_reset() > > which call inquiry_cache_flush(). If the discovery state is not set > > correctly through these code paths you might get into a situation where > > you can't start discovery again after doing "hciconfig hci0 reset" or > > "hciconfig hci0 down" while discovery was active. So I agree that some > > fix is needed but you need to ensure that you don't break these use > > cases. > > This issue is already address by upstream patch "Bluetooth: Set > DISCOVERY_STOPPED if controller resets". So, the discovery state machine > will be right even if we run "hciconfig hci0 reset" or "hciconfig hci0 > down" while discovery is active. I didn't realize this has been added to the cc_reset function. In that case I think both use cases should be fine with this patch, i.e. I change my nack to an ack :) Johan -- 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
