[PATCH 5.17 27/39] Bluetooth: hci_sync: Add a new quirk to skip HCI_FLT_CLEAR_ALL

Greg Kroah-Hartman
2022-03-25T15:34:36Z

From: Ismael Ferreras Morezuelas <swyterzone@gmail.com>

commit 0eaecfb2e4814d51ab172df3823e35d7c488b6d2 upstream.

Some controllers have problems with being sent a command to clear
all filtering. While the HCI code does not unconditionally
send a clear-all anymore at BR/EDR setup (after the state machine
refactor), there might be more ways of hitting these codepaths
in the future as the kernel develops.

Cc: stable@vger.kernel.org
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Ismael Ferreras Morezuelas <swyterzone@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/net/bluetooth/hci.h | 10 ++++++++++
net/bluetooth/hci_sync.c | 16 ++++++++++++++++
2 files changed, 26 insertions(+)

--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -255,6 +255,16 @@ enum {
* during the hdev->setup vendor callback.
*/
HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER,
+
+ /* When this quirk is set, HCI_OP_SET_EVENT_FLT requests with
+ * HCI_FLT_CLEAR_ALL are ignored and event filtering is
+ * completely avoided. A subset of the CSR controller
+ * clones struggle with this and instantly lock up.
+ *
+ * Note that devices using this must (separately) disable
+ * runtime suspend, because event filtering takes place there.
+ */
+ HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL,
};

/* HCI device flags */
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -2806,6 +2806,9 @@ static int hci_set_event_filter_sync(str
if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED))
return 0;

+ if (test_bit(HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL, &hdev->quirks))
+ return 0;
+
memset(&cp, 0, sizeof(cp));
cp.flt_type = flt_type;

@@ -2826,6 +2829,13 @@ static int hci_clear_event_filter_sync(s
if (!hci_dev_test_flag(hdev, HCI_EVENT_FILTER_CONFIGURED))
return 0;

+ /* In theory the state machine should not reach here unless
+ * a hci_set_event_filter_sync() call succeeds, but we do
+ * the check both for parity and as a future reminder.
+ */
+ if (test_bit(HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL, &hdev->quirks))
+ return 0;
+
return hci_set_event_filter_sync(hdev, HCI_FLT_CLEAR_ALL, 0x00,
BDADDR_ANY, 0x00);
}
@@ -4825,6 +4835,12 @@ static int hci_update_event_filter_sync(
if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED))
return 0;

+ /* Some fake CSR controllers lock up after setting this type of
+ * filter, so avoid sending the request altogether.
+ */
+ if (test_bit(HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL, &hdev->quirks))
+ return 0;
+
/* Always clear event filter when starting */
hci_clear_event_filter_sync(hdev);