Pandaboard ES freezes with CPU scaling governor ondemand

[Paul W Panish]

SRU Justification:

    Impact: people that forces the use of the ONDEMAND governor can incur in system freeze after a while.
    Fix: disable ONDEMAND module compilation.
    Testcase: see http://bugs.launchpad.net/bugs/971091 for a test case.

===

Bug https://bugs.launchpad.net/ubuntu/+source/linux-ti-omap4/+bug/971091 appears to have been "fixed" by making the default frequency scaling setting "performance". This sets the processors to a fixed clock, but does not address the underlying crash when scaling is being used to vary the processor clock to match demand.

[Paolo Pisati (p-pisati)]

which kernel version?

besides, the fix requires backporting a lot of code from Q and it won't happen for P and O.

[Paul W Panish (ppanish)]

Here's version information for the failing system. Could you describe the meaning of O, P, and Q? I assume these are branches. but I'm not building kernels at this point, just trying to use what's out there.

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=12.04
DISTRIB_CODENAME=precise
DISTRIB_DESCRIPTION="Ubuntu 12.04.1 LTS"
ppanish@ppanda:~$ uname -a
Linux ppanda 3.2.0-1419-omap4 #26-Ubuntu SMP PREEMPT Wed Sep 12 14:32:40 UTC 2012 armv7l armv7l armv7l GNU/Linux

[Paul W Panish (ppanish)]

Oh, I guess this must be Oneric, Precise, and whatever's coming up next.

[Paolo Pisati (p-pisati)]

As i said in #1, to properly fix this bug we would need to backport way too much code from Q thus it won't happen for P.

Anyhow, to put this problem to rest _forever_, i just submitted a patch that disabled compilation of the ONDEMAND governor in P.
If you really want to use ONDEMAND, upgrade to Quantal.

[Herton R. Krzesinski (herton)]

Verified:

$ dpkg-deb -c linux-image-3.2.0-1422-omap4_3.2.0-1422.29_armel.deb | grep ondemand
-rw-r--r-- root/root 16648 2012-11-22 15:25 ./lib/modules/3.2.0-1422-omap4/kernel/drivers/cpufreq/cpufreq_ondemand.ko
$ dpkg-deb -c linux-image-3.2.0-1422-omap4_3.2.0-1422.29_armhf.deb | grep ondemand
-rw-r--r-- root/root 16648 2012-11-22 15:20 ./lib/modules/3.2.0-1422-omap4/kernel/drivers/cpufreq/cpufreq_ondemand.ko
$ dpkg-deb -c linux-image-3.2.0-1423-omap4_3.2.0-1423.30_armel.deb | grep ondemand
$ dpkg-deb -c linux-image-3.2.0-1423-omap4_3.2.0-1423.30_armhf.deb | grep ondemand
$

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-ti-omap4 - 3.2.0-1423.30

---------------
linux-ti-omap4 (3.2.0-1423.30) precise-proposed; urgency=low

  * Release Tracking Bug
    - LP: #1087211

  [ Paolo Pisati ]

  * rebased on Ubuntu-3.2.0-35.55

  [ Tim Gardner ]

  * [Config] CONFIG_CPU_FREQ_GOV_ONDEMAND=n
    - LP: #1059555

  [ Ubuntu: 3.2.0-35.55 ]

  * Release Tracking Bug
    - LP: #1086856
  * Revert "SAUCE: ata_piix: add a disable_driver option"
    - LP: #1079084
  * Revert "SAUCE: ata_piix: defer disks to the Hyper-V drivers by default"
    - LP: #1079084
  * SAUCE: ata_piix: add a disable_driver option
    - LP: #1079084, #994870
  * libata: add a host flag to ignore detected ATA devices
    - LP: #1079084
  * ata_piix: defer disks to the Hyper-V drivers by default
    - LP: #1079084, #929545, #942316

  [ Ubuntu: 3.2.0-35.54 ]

  * Release Tracking Bug
    - LP: #1086349
  * Revert "SAUCE: SECCOMP: audit: always report seccomp violations"
    - LP: #1079469
  * SAUCE: SECCOMP: audit: fix build on archs without CONFIG_AUDITSYSCALL
    - LP: #1079469
  * seccomp: forcing auditing of kill condition
    - LP: #1079469
  * Bluetooth: Avoid calling undefined smp_conn_security()
    - LP: #1081676
  * x86: Remove the ancient and deprecated disable_hlt() and enable_hlt()
    facility
    - LP: #1081676
  * drm/nouveau: silence modesetting spam on pre-gf8 chipsets
    - LP: #1081676
  * drm/nouveau: fix suspend/resume when in headless mode
    - LP: #1081676
  * drm/nouveau: headless mode by default if pci class != vga display
    - LP: #1081676
  * nfsd: add get_uint for u32's
    - LP: #1081676
  * ALSA: PCM: Fix some races at disconnection
    - LP: #1081676
  * ALSA: usb-audio: Fix races at disconnection
    - LP: #1081676
  * ALSA: usb-audio: Use rwsem for disconnect protection
    - LP: #1081676
  * ALSA: usb-audio: Fix races at disconnection in mixer_quirks.c
    - LP: #1081676
  * ALSA: Add a reference counter to card instance
    - LP: #1081676
  * ALSA: Avoid endless sleep after disconnect
    - LP: #1081676
  * drm/radeon: fix typo in evergreen_mc_resume()
    - LP: #1081676
  * USB: mos7840: remove unused variable
    - LP: #1081676
  * rtnetlink: Fix problem with buffer allocation
    - LP: #1081676
  * rtnetlink: fix rtnl_calcit() and rtnl_dump_ifinfo()
    - LP: #1081676
  * gpio-timberdale: fix a potential wrapping issue
    - LP: #1081676
  * cfg80211: fix antenna gain handling
    - LP: #1081676
  * drm/i915: fix overlay on i830M
    - LP: #1081676
  * drm/i915: fixup infoframe support for sdvo
    - LP: #1081676
  * drm/i915: clear the entire sdvo infoframe buffer
    - LP: #1081676
  * crypto: cryptd - disable softirqs in cryptd_queue_worker to prevent
    data corruption
    - LP: #1081676
  * ARM: at91: at91sam9g10: fix SOC type detection
    - LP: #1081676
  * ARM: at91/i2c: change id to let i2c-gpio work
    - LP: #1081676
  * mac80211: Only process mesh config header on frames that RA_MATCH
    - LP: #1081676
  * mac80211: don't inspect Sequence Control field on control frames
    - LP: #1081676
  * mac80211: fix SSID copy on IBSS JOIN
    - LP: #1081676
  * wireless: drop invalid mesh address extension frames
    - ...

[Adam Conrad (adconrad)]

The verification of this Stable Release Update has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regresssions.