ubuntu kernel hirsute-proposed 5.11.0-19 does not work. I believe backporting patches to such an old kernel was a mistake. You should have consulted Pierre-Louis Bossart <<email address hidden> if backporting patches to 5.11 is a good idea, what problems could arise or if the 5.11 kernel has everything the patches require.
ubuntu kernel hirsute-proposed 5.11.0-19 does not work. I believe backporting patches to such an old kernel was a mistake. You should have consulted Pierre-Louis Bossart <<email address hidden> if backporting patches to 5.11 is a good idea, what problems could arise or if the 5.11 kernel has everything the patches require.