I did some research and noticed that this only seems to happen on the Nexus 4. On the Nexus 5 (Android 4.4.4), reading the same sysfs file actually yields a result:
shell@hammerhead:/ $ cat /sys/devices/system/cpaccess/cpaccess0/cp_rw 512f06f0 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-mako in Ubuntu. https://bugs.launchpad.net/bugs/1425290 Title: Reading from /sys/devices/system/cpaccess/cpaccess0/cp_rw crashes the Nexus 4 Status in linux-mako package in Ubuntu: New Bug description: I noticed that my Nexus 4 crashed while doing a grep "1" -r / in an adb shell as user phablet. After narrowing it down, it looks like I can reliably crash my device by just doing a cat /sys/devices/system/cpaccess/cpaccess0/cp_rw as a normal user. After doing it about three times, all aspects of the device still work as expected, but it no longer identifies itself via USB, not even when in recovery mode. This might be a different issue, but it has never happened before, so I do think it might have been caused by the crashes. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-mako/+bug/1425290/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
