Ritmix RWA-350 fix for Ubuntu 22.04

readme.md

The patch mentioned in this thread helped get the Ritmix RWA-350 working on Ubuntu 22.04.

Shown in lsusb as:

ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)

I cleaned up the patch (see file below).

Extract the linux-source archive corresponding to your kernel and do the following:

$ patch -p1 < csr-clean.patch
$ make -C /lib/modules/$(uname -r)/build M=$(pwd)/net/bluetooth ccflags-y="$(echo "-include "$(pwd)/include/net/bluetooth/{bluetooth.h,hci.h})" modules
$ make -C /lib/modules/$(uname -r)/build M=$(pwd)/drivers/bluetooth ccflags-y="$(echo "-include "$(pwd)/include/net/bluetooth/{bluetooth.h,hci.h})" modules
$ strip --strip-debug net/bluetooth/bluetooth.ko
$ strip --strip-debug drivers/bluetooth/btusb.ko

Then you can replace the old drivers in /usr/lib/modules/$(uname -r)/kernel with the new ones. Don't forget to backup the old files.

csr-clean.patch

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 8c41c76..9632251 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -1979,6 +1979,8 @@ static int btusb_setup_csr(struct hci_dev *hdev)
 		 */
 		set_bit(HCI_QUIRK_BROKEN_STORED_LINK_KEY, &hdev->quirks);
 		set_bit(HCI_QUIRK_BROKEN_ERR_DATA_REPORTING, &hdev->quirks);
+		set_bit(HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL, &hdev->quirks);
+		set_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks);
 
 		/* Clear the reset quirk since this is not an actual
 		 * early Bluetooth 1.1 device from CSR.
@@ -2018,7 +2020,7 @@ static int btusb_setup_csr(struct hci_dev *hdev)
 		if (ret >= 0)
 			msleep(200);
 		else
-			bt_dev_err(hdev, "CSR: Failed to suspend the device for our Barrot 8041a02 receive-issue workaround");
+			bt_dev_warn(hdev, "CSR: Couldn't suspend the device for our Barrot 8041a02 receive-issue workaround");
 
 		pm_runtime_forbid(&data->udev->dev);
 
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 9ce46cb..b97602a 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -255,6 +255,7 @@ enum {
 	 * during the hdev->setup vendor callback.
 	 */
 	HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER,
+	HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL,
 };
 
 /* HCI device flags */
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index bb84ff5..2a7af9a 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -294,6 +294,7 @@ static void bredr_setup(struct hci_request *req)
 
 	/* Clear Event Filters */
 	flt_type = HCI_FLT_CLEAR_ALL;
+	if (!test_bit(HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL, &req->hdev->quirks))
 	hci_req_add(req, HCI_OP_SET_EVENT_FLT, 1, &flt_type);
 
 	/* Connection accept timeout ~20 secs */
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index c2db60a..39a871a 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -1160,6 +1160,9 @@ static void hci_req_clear_event_filter(struct hci_request *req)
 	if (!hci_dev_test_flag(req->hdev, HCI_BREDR_ENABLED))
 		return;
 
+	if (test_bit(HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL, &req->hdev->quirks))
+		return;
+
 	if (hci_dev_test_flag(req->hdev, HCI_EVENT_FILTER_CONFIGURED)) {
 		memset(&f, 0, sizeof(f));
 		f.flt_type = HCI_FLT_CLEAR_ALL;
@@ -1178,6 +1181,9 @@ static void hci_req_set_event_filter(struct hci_request *req)
 	if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED))
 		return;
 
+	if (test_bit(HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL, &hdev->quirks))
+		return;
+
 	/* Always clear event filter when starting */
 	hci_req_clear_event_filter(req);