Hi Mattijs, > During the setup() stage, HCI device drivers expect the chip to > acknowledge its setup() completion via vendor specific frames. > > If userspace opens() such HCI device in HCI_USER_CHANNEL [1] mode, > the vendor specific frames are never tranmitted to the driver, as > they are filtered in hci_rx_work(). > > Allow HCI devices which operate in HCI_USER_CHANNEL mode to receive > frames if the HCI device is is HCI_INIT state. > > [1] https://www.spinics.net/lists/linux-bluetooth/msg37345.html > > Fixes: 23500189d7e0 ("Bluetooth: Introduce new HCI socket channel for user operation") > Signed-off-by: Mattijs Korpershoek <mkorpershoek@xxxxxxxxxxxx> > --- > Changelog: > v2: > * change test logic to transfer packets when in INIT phase > for user channel mode as recommended by Marcel > * renamed patch from > "Bluetooth: hci_core: fix init with HCI_QUIRK_NON_PERSISTENT_SETUP" > > v1: > * https://lkml.org/lkml/2019/10/3/2250 > > Some more background on the change follows: > > The Android bluetooth stack (Bluedroid) also has a HAL implementation > which follows Linux's standard rfkill interface [1]. > > This implementation relies on the HCI_CHANNEL_USER feature to get > exclusive access to the underlying bluetooth device. > > When testing this along with the btkmtksdio driver, the > chip appeared unresponsive when calling the following from userspace: > > struct sockaddr_hci addr; > int fd; > > fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); > > memset(&addr, 0, sizeof(addr)); > addr.hci_family = AF_BLUETOOTH; > addr.hci_dev = 0; > addr.hci_channel = HCI_CHANNEL_USER; > > bind(fd, (struct sockaddr *) &addr, sizeof(addr)); # device hangs > > In the case of bluetooth drivers exposing QUIRK_NON_PERSISTENT_SETUP > such as btmtksdio, setup() is called each multiple times. > In particular, when userspace calls bind(), the setup() is called again > and vendor specific commands might be send to re-initialize the chip. > > Those commands are filtered out by hci_core in HCI_CHANNEL_USER mode, > preventing setup() from completing successfully. > > This has been tested on a 4.19 kernel based on Android Common Kernel. > It has also been compile tested on bluetooth-next. > > [1] https://android.googlesource.com/platform/system/bt/+/refs/heads/master/vendor_libs/linux/interface/ > > net/bluetooth/hci_core.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) patch has been applied to bluetooth-next tree. Regards Marcel
