From: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx>
Some drivers depend on shutdown being called for proper operation.
Unset HCI_USER_CHANNEL and call the full close routine since shutdown is
complementary to setup.
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx>
---
Using hci_qca, we can get the controller into a bad state simply by
trying to bind to userchannel twice (open+bind+close, then open+bind).
Without running the shutdown routine, the device seems to get into a bad
state. A similar bug also occurs with btmtksdio (using MT7921).
This change properly runs the shutdown routine, which should be
complementary to setup. The reason it unsets the HCI_USER_CHANNEL flag
is that some drivers have complex operations in their shutdown routine
(including sending hci packets) and we need to support the normal data
path for them (including cmd_timeout + recovery mechanisms).
Note for v2: I've gotten a chance to test this on more devices
and figure out why it wasn't working before in v1. I found two problems:
I had a signal pending (SIGTERM) that was messing things up in the
socket release function and the HCI_USER_CHANNEL flag was preventing
hci_sync from operating properly during shutdown on Intel chipsets
(which use the sync functions to send a reset command + other commands
sometimes).
This was tested with hci_qca (QCA6174-A-3), btmtksdio (MT7921-SDIO)
and btusb (with AX200).
Changes in v2:
- Clear HCI_USER_CHANNEL flag at start of close and restore at end.
- Add comment explaning why we need to clear flag and run shutdown.
net/bluetooth/hci_sync.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 422f7c6911d9..f9591fcefb8d 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -4731,9 +4731,18 @@ int hci_dev_close_sync(struct hci_dev *hdev)
{
bool auto_off;
int err = 0;
+ bool was_userchannel;
bt_dev_dbg(hdev, "");
+ /* Similar to how we first do setup and then set the exclusive access
+ * bit for userspace, we must first unset userchannel and then clean up.
+ * Otherwise, the kernel can't properly use the hci channel to clean up
+ * the controller (some shutdown routines require sending additional
+ * commands to the controller for example).
+ */
+ was_userchannel = hci_dev_test_and_clear_flag(hdev, HCI_USER_CHANNEL);
+
cancel_delayed_work(&hdev->power_off);
cancel_delayed_work(&hdev->ncmd_timer);
cancel_delayed_work(&hdev->le_scan_disable);
@@ -4747,7 +4756,6 @@ int hci_dev_close_sync(struct hci_dev *hdev)
}
if (!hci_dev_test_flag(hdev, HCI_UNREGISTER) &&
- !hci_dev_test_flag(hdev, HCI_USER_CHANNEL) &&
test_bit(HCI_UP, &hdev->flags)) {
/* Execute vendor specific shutdown routine */
if (hdev->shutdown)
@@ -4756,6 +4764,8 @@ int hci_dev_close_sync(struct hci_dev *hdev)
if (!test_and_clear_bit(HCI_UP, &hdev->flags)) {
cancel_delayed_work_sync(&hdev->cmd_timer);
+ if (was_userchannel)
+ hci_dev_set_flag(hdev, HCI_USER_CHANNEL);
return err;
}
@@ -4795,7 +4805,7 @@ int hci_dev_close_sync(struct hci_dev *hdev)
auto_off = hci_dev_test_and_clear_flag(hdev, HCI_AUTO_OFF);
if (!auto_off && hdev->dev_type == HCI_PRIMARY &&
- !hci_dev_test_flag(hdev, HCI_USER_CHANNEL) &&
+ !was_userchannel &&
hci_dev_test_flag(hdev, HCI_MGMT))
__mgmt_power_off(hdev);
@@ -4808,7 +4818,7 @@ int hci_dev_close_sync(struct hci_dev *hdev)
hci_sock_dev_event(hdev, HCI_DEV_DOWN);
- if (!hci_dev_test_flag(hdev, HCI_USER_CHANNEL)) {
+ if (!was_userchannel)
aosp_do_close(hdev);
msft_do_close(hdev);
}
@@ -4858,6 +4868,9 @@ int hci_dev_close_sync(struct hci_dev *hdev)
memset(hdev->dev_class, 0, sizeof(hdev->dev_class));
bacpy(&hdev->random_addr, BDADDR_ANY);
+ if (was_userchannel)
+ hci_dev_set_flag(hdev, HCI_USER_CHANNEL);
+
hci_dev_put(hdev);
return err;
}
--
2.37.3.998.g577e59143f-goog
