Hi Johan, On Thu, Mar 1, 2012 at 7:32 PM, Johan Hedberg <johan.hedberg@xxxxxxxxx> wrote: > Hi Andre, > > 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. BR, Andre -- 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
