usb/188829: atp fails on Macbook Pro 4.1

[Roberto de Iriarte]

>Number:         188829
>Category:       usb
>Synopsis:       atp fails on Macbook Pro 4.1
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-usb
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sun Apr 20 16:10:00 UTC 2014
>Closed-Date:
>Last-Modified:
>Originator:     Roberto de Iriarte
>Release:        10.0-STABLE
>Organization:
De Iriarte
>Environment:
FreeBSD mbp 10.0-STABLE FreeBSD 10.0-STABLE #13 r264692M: Sun Apr 20 12:14:28 CLST 2014     root at mbp:/usr/obj/usr/src/sys/GENERIC  amd64
>Description:
On my Macbook Pro 4.1, after upgrading from 10.0-RELEASE to 10.0-STABLE, the atp touchpad driver becomes unresponsive after a few minutes under high I/O load, until it stalls completely. The device never unstalls, regardless of system load. 

Closing and opening /dev/atp0 (i.e. restarting moused) restores responsiveness for a couple of minutes, then it fails in the same manner.

Reverting back /usr/src/sys/dev/usb/input/atp.c from rev. 263063 to rev. 233774 (as shipped with FreeBSD 10.0-RELEASE) solves the problem completely on my machine.

Unfortunately, i am not versed in the workings of the atp driver in order to debug the new driver any further.
>How-To-Repeat:
Use the trackpad under high I/O load
>Fix:
Hack: Revert back to /usr/src/sys/dev/usb/input/atp.c as shipped with 10.0-RELEASE (r. 233774)

>Release-Note:
>Audit-Trail:
>Unformatted: