Excerpt from /var/log/syslog in case this is of interest:
[ 4964.004717] psmouse serio1: >alps: E6 report: 00 00 64 [ 4964.022968] psmouse serio1: >alps: E7 report: 73 03 0a [ 4964.038963] psmouse serio1: >alps: Model=24, proto_version=4
Excerpt from /var/log/syslog in case this is of interest:
[ 4964.004717] psmouse serio1: >alps: E6 report: 00 00 64
[ 4964.022968] psmouse serio1: >alps: E7 report: 73 03 0a
[ 4964.038963] psmouse serio1: >alps: Model=24, proto_version=4