After changing governor to "performance", crashes were still appearing.
However, I traced this to be most likely caused by CPU overheating. /var/log/syslog.* recorded messages like omap_monitor_zone:hot spot temp 86874, and even temperatures over 100 C. This is just a reminder to all who switch to performance mode: remember to attach a heat sink! -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-ti-omap4 in Ubuntu. https://bugs.launchpad.net/bugs/971091 Title: Pandaboard ES freezes with the default CPU scaling governor ondemand Status in Linaro Texas Instruments Landing Team: Fix Released Status in Linaro Ubuntu Engineering Builds: Fix Released Status in “linux-ti-omap4” package in Ubuntu: Fix Released Bug description: Pandaboard ES freezes sporadically with the CPU scaling governor default setting, which is "ondemand". It is a complete freeze, no syslog entry, no serial access, no network, no keyboard/mouse anymore. When pressing the reset button, it will not even reboot. The SD card interface seems to be hanging. Pulling and re-inserting the SD card before pressing the reset button, or a global power-cycle will re-boot the board properly. The error occurs during normal operation on desktop, but can also be procuded in an unattended way: 1. Create a RAM disk by adding this to fstab none /tmp tmpfs defaults,noatime,mode=1777,size=600M 0 0 2. Mount it and create a big file on the RAM disk: dd bs=1M count=210 if=/dev/urandom of=/tmp/a 3. Change to /tmp and start an endless loop: while true; do cp a b; date; sleep 3; done Note that the "sleep" is important to cause the governor to switch CPU speed up and down. Wait for 1 to 8 hrs and find the Pandaboard ES in frozen state. You can do the same with a bigger file and /tmp on the SD card. This will often produce the error faster (possibly due to CPU idling at flash write delays) but will stress your flash card. Setting the CPU scaling governor to "performance" completely solves the problem. I guess there might be a HW issue on the Pandaboard ES that kicks in with frequent CPU speed changes. Solution proposal: set the CPU scaling governor to "performance" as default until the issue is further analysed. ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: linux-image-3.2.0-1411-omap4 3.2.0-1411.14 ProcVersionSignature: Ubuntu 3.2.0-1411.14-omap4 3.2.9 Uname: Linux 3.2.0-1411-omap4 armv7l ApportVersion: 1.95-0ubuntu1 Architecture: armhf Date: Sun Apr 1 23:01:52 2012 ProcEnviron: TERM=xterm LANG=de_DE.UTF-8 SHELL=/bin/bash SourcePackage: linux-ti-omap4 UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-landing-team-ti/+bug/971091/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
