This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- vivid' to 'verification-done-vivid'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: verification-needed-vivid -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1457781 Title: armhf: cpufreq doesn't autoload by default Status in linux package in Ubuntu: Fix Released Status in linux source package in Utopic: Fix Committed Status in linux source package in Vivid: Fix Committed Bug description: SRU Justification: Impact: upon boot, frequency scaling is not working. Fix: Apply the patches, recompile and reboot. Testcase: Try booting a beaglebone with and without a patched kernel. With this series applied there should be: ubuntu@beaglebone:~$ ls -la /sys/devices/system/cpu/cpu0/cpufreq/ total 0 drwxr-xr-x 3 root root 0 May 22 07:03 . drwxr-xr-x 5 root root 0 May 22 07:03 .. -r--r--r-- 1 root root 4096 May 22 07:03 affected_cpus -r-------- 1 root root 4096 May 22 07:03 cpuinfo_cur_freq -r--r--r-- 1 root root 4096 May 22 07:03 cpuinfo_max_freq -r--r--r-- 1 root root 4096 May 22 07:03 cpuinfo_min_freq -r--r--r-- 1 root root 4096 May 22 07:03 cpuinfo_transition_latency -r--r--r-- 1 root root 4096 May 22 07:03 related_cpus -r--r--r-- 1 root root 4096 May 22 07:03 scaling_available_frequencies -r--r--r-- 1 root root 4096 May 22 07:03 scaling_available_governors -r--r--r-- 1 root root 4096 May 22 07:03 scaling_cur_freq -r--r--r-- 1 root root 4096 May 22 07:03 scaling_driver -rw-r--r-- 1 root root 4096 May 22 04:43 scaling_governor -rw-r--r-- 1 root root 4096 May 22 07:03 scaling_max_freq -rw-r--r-- 1 root root 4096 May 22 07:03 scaling_min_freq -rw-r--r-- 1 root root 4096 May 22 07:03 scaling_setspeed drwxr-xr-x 2 root root 0 May 22 07:03 stats ubuntu@beaglebone:~$ With an unpatched kernel, until the cpufreq module is loaded, that directory doesn't exist. ... While cpufreq support on armhf is available for a while, if support is compiled as a kernel module, the corresponding module doesn't autoload by default, and thus frequency scaling is not active upon boot until a user manually load it (or until /etc/modules is modified to forcibly load it). While in Trusty cpufreq was built-in on armhf, starting with Utopic we made support available as a kernel module, making people think that cpufreq was either broken or missing in their new kernels. To fix it, revert back that decision and make cpufreq compiled-in again on armhf - it affects Utopic and Vivid kernels. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1457781/+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
