Patches the linux bluetooth driver to handle dongles that report they are CSR, but really aren't

patch-bluetooth-driver.sh

#!/usr/bin/env bash
# https://askubuntu.com/questions/1168123/how-do-i-get-my-bluetooth-device-working/1192200#1192200
set -e

SCRIPTDIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )

main() {
  local kernver
  kernver=$(uname -r)
  sudo apt update
  rm -rf "$SCRIPTDIR"/linux{-,_}*
  apt source linux

  local drvdir="$SCRIPTDIR/linux-${kernver/%-*}/drivers/bluetooth"
  patch -d "$drvdir" <<<"--- btusb.c	2021-01-28 10:00:00.000000000 +0000
+++ btusb.c	2021-01-28 10:00:00.000000000 +0000
@@ -1642,8 +1642,8 @@
 	rp = (struct hci_rp_read_local_version *)skb->data;

 	/* Detect controllers which aren't real CSR ones. */
-	if (le16_to_cpu(rp->manufacturer) != 10 ||
-	    le16_to_cpu(rp->lmp_subver) == 0x0c5c) {
+	/* if (le16_to_cpu(rp->manufacturer) != 10 ||
+	    le16_to_cpu(rp->lmp_subver) == 0x0c5c) */ {
 		/* Clear the reset quirk since this is not an actual
 		 * early Bluetooth 1.1 device from CSR.
 		 */
@@ -3899,7 +3899,7 @@
 			set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);

 		/* Fake CSR devices with broken commands */
-		if (bcdDevice <= 0x100 || bcdDevice == 0x134)
+		// if (bcdDevice <= 0x100 || bcdDevice == 0x134)
 			hdev->setup = btusb_setup_csr;

 		set_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks);
"
  make -C "/lib/modules/$kernver/build" M="$drvdir" clean
  cp "/usr/src/linux-headers-$kernver/.config" "$drvdir/"
  cp "/usr/src/linux-headers-$kernver/Module.symvers" "$drvdir/Module.symvers"
  make -C "/lib/modules/$kernver/build" M="$drvdir" modules

  local backupdir="$SCRIPTDIR/backup/$kernver"
  mkdir -p "$backupdir"
  sudo cp "/lib/modules/$kernver/kernel/drivers/bluetooth/btusb.ko" "$backupdir/btusb.ko"

  sudo cp "$drvdir/btusb.ko" "/lib/modules/$kernver/kernel/drivers/bluetooth/btusb.ko"
  sudo modprobe -r btusb
  sudo modprobe -v btusb
}

main "$@"

metod don't work