It looks like the C15B laptop got another vendor: ByteSpeed LLC.

Avoid AUX loopback on this touchpad as well, thus input subsystem will
be able to recognize a Synaptics touchpad in the AUX port.

BugLink: https://bugs.launchpad.net/bugs/1906128Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
Link: https://lore.kernel.org/r/20201201054723.5939-1-po-hsu.lin@canonical.com
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>