Subject: port-hpcmips/30748: Screen freezes after suspend/resume with ITE8181_LCD_CONTROL_ENABLE
To: None <email@example.com, firstname.lastname@example.org,>
From: None <email@example.com>
Date: 07/14/2005 16:54:01
>Synopsis: Screen freezes after suspend/resume with ITE8181_LCD_CONTROL_ENABLE
>Arrival-Date: Thu Jul 14 16:54:00 +0000 2005
>Originator: Svend Sorensen
>Release: NetBSD 2.0.2
NetBSD ink.fakedomain.com 2.0.0_STABLE NetBSD 2.0.2_STABLE (IBMZ50) #0 Tue Jul5 16:27:47 PDT 2005 sorensen@sverige:/tmp/sorensen/src/sys/arch/hpcmips/compile/IBMz50 hpcmips
With ITE8181_LCD_CONTROL_ENABLE option set, the screen on the IBM Z50 will blank when the system suspends. The system normally resumes without any problems. The power button initiates a suspend, and wakes the system up if it is suspended.
Occasionally, when resuming, the screen will display a set of vertical bars, and the system will be unresponsive. The power button does not re-suspend the machine, and a hard reset (remove power cable, remove battery) is required.
The port-hpcmips mailing list has several posts regarding this issue. Search the list for the string "vertical bars" (http://search.gmane.org/?query=vertical+bars&group=gmane.os.netbsd.ports.hpcmips).
I patched my kernel with the 'TLB out of universe' fix at http://www.city-net.com/~darkstar/netbsd/hpcmips.diff (see http://mail-index.netbsd.org/port-hpcmips/2004/12/30/0003.html). I added the line:
to the GENERIC kernel config and rebuilt it.
Enable ITE8181_LCD_CONTROL_ENABLE (see http://netbsd.org/Ports/hpcmips/faq.html#z50-lcd). Suspend the IBM Z50 by pressing the power button. Resume the IBM Z50 by pressing the power button again. Repeat until the screen displays vertical bars on resume.
Members of the port-hpcmips list suggested that running sync before suspending greatly reduced the probability of the issue arrising, but I did not find this to be the case. When 'sync' did not work, I set up all partitions as read only, with mfs for /tmp and /var. This eliminated any writes to the CF card, but the problem still arose.