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  1. Mar 08, 2014
    • Rafael J. Wysocki's avatar
      Merge branch 'pm-cpufreq' · 19bc45a5
      Rafael J. Wysocki authored 
      * pm-cpufreq:
  cpufreq: Initialize governor for a new policy under policy->rwsem
  cpufreq: Initialize policy before making it available for others to use
  cpufreq: use cpufreq_cpu_get() to avoid cpufreq_get() race conditions
      19bc45a5
    • Rafael J. Wysocki's avatar
      Merge branches 'acpi-resources', 'acpi-ec' and 'acpi-sleep' · beb0082e
      Rafael J. Wysocki authored 
      * acpi-resources:
  ACPI / resources: ignore invalid ACPI device resources

* acpi-ec:
  ACPI / EC: Clear stale EC events on Samsung systems

* acpi-sleep:
  ACPI / sleep: pm_power_off needs more sanity checks to be installed
      beb0082e
  3. Mar 06, 2014
    • Kieran Clancy's avatar
      ACPI / EC: Clear stale EC events on Samsung systems · ad332c8a
      Kieran Clancy authored 
      A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc)
continue to log events during sleep (lid open/close, AC plug/unplug,
battery level change), which accumulate in the EC until a buffer fills.
After the buffer is full (tests suggest it holds 8 events), GPEs stop
being triggered for new events. This state persists on wake or even on
power cycle, and prevents new events from being registered until the EC
is manually polled.

This is the root cause of a number of bugs, including AC not being
detected properly, lid close not triggering suspend, and low ambient
light not triggering the keyboard backlight. The bug also seemed to be
responsible for performance issues on at least one user's machine.

Juan Manuel Cabo found the cause of bug and the workaround of polling
the EC manually on wake.

The loop which clears the stale events is based on an earlier patch by
Lan Tianyu (see referenced attachment).

This patch:
 - Adds a function acpi_ec_clear() which polls the EC for stale _Q
   events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is
   logged if this limit is reached.
 - Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI
   system vendor is Samsung. This check could be replaced by several
   more specific DMI vendor/product pairs, but it's likely that the bug
   affects more Samsung products than just the five series mentioned
   above. Further, it should not be harmful to run acpi_ec_clear() on
   systems without the bug; it will return immediately after finding no
   data waiting.
 - Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add()
 - Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions()

References: https://bugzilla.kernel.org/show_bug.cgi?id=44161
References: https://bugzilla.kernel.org/show_bug.cgi?id=45461
References: https://bugzilla.kernel.org/show_bug.cgi?id=57271
References: https://bugzilla.kernel.org/attachment.cgi?id=126801


Suggested-by: default avatarJuan Manuel Cabo <juanmanuel.cabo@gmail.com>
Signed-off-by: default avatarKieran Clancy <clancy.kieran@gmail.com>
Reviewed-by: default avatarLan Tianyu <tianyu.lan@intel.com>
Reviewed-by: default avatarDennis Jansen <dennis.jansen@web.de>
Tested-by: default avatarKieran Clancy <clancy.kieran@gmail.com>
Tested-by: default avatarJuan Manuel Cabo <juanmanuel.cabo@gmail.com>
Tested-by: default avatarDennis Jansen <dennis.jansen@web.de>
Tested-by: default avatarMaurizio D'Addona <mauritiusdadd@gmail.com>
Tested-by: default avatarSan Zamoyski <san@plusnet.pl>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      ad332c8a
    • Viresh Kumar's avatar
      cpufreq: Initialize governor for a new policy under policy->rwsem · 4e97b631
      Viresh Kumar authored 
      

policy->rwsem is used to lock access to all parts of code modifying
struct cpufreq_policy, but it's not used on a new policy created by
__cpufreq_add_dev().

Because of that, if cpufreq_update_policy() is called in a tight loop
on one CPU in parallel with offline/online of another CPU, then the
following crash can be triggered:

Unable to handle kernel NULL pointer dereference at virtual address 00000020
pgd = c0003000
[00000020] *pgd=80000000004003, *pmd=00000000
Internal error: Oops: 206 [#1] PREEMPT SMP ARM

PC is at __cpufreq_governor+0x10/0x1ac
LR is at cpufreq_update_policy+0x114/0x150

---[ end trace f23a8defea6cd706 ]---
Kernel panic - not syncing: Fatal exception
CPU0: stopping
CPU: 0 PID: 7136 Comm: mpdecision Tainted: G      D W    3.10.0-gd727407-00074-g979ede8 #396

[<c0afe180>] (notifier_call_chain+0x40/0x68) from [<c02a23ac>] (__blocking_notifier_call_chain+0x40/0x58)
[<c02a23ac>] (__blocking_notifier_call_chain+0x40/0x58) from [<c02a23d8>] (blocking_notifier_call_chain+0x14/0x1c)
[<c02a23d8>] (blocking_notifier_call_chain+0x14/0x1c) from [<c0803c68>] (cpufreq_set_policy+0xd4/0x2b8)
[<c0803c68>] (cpufreq_set_policy+0xd4/0x2b8) from [<c0803e7c>] (cpufreq_init_policy+0x30/0x98)
[<c0803e7c>] (cpufreq_init_policy+0x30/0x98) from [<c0805a18>] (__cpufreq_add_dev.isra.17+0x4dc/0x7a4)
[<c0805a18>] (__cpufreq_add_dev.isra.17+0x4dc/0x7a4) from [<c0805d38>] (cpufreq_cpu_callback+0x58/0x84)
[<c0805d38>] (cpufreq_cpu_callback+0x58/0x84) from [<c0afe180>] (notifier_call_chain+0x40/0x68)
[<c0afe180>] (notifier_call_chain+0x40/0x68) from [<c02812dc>] (__cpu_notify+0x28/0x44)
[<c02812dc>] (__cpu_notify+0x28/0x44) from [<c0aeed90>] (_cpu_up+0xf4/0x1dc)
[<c0aeed90>] (_cpu_up+0xf4/0x1dc) from [<c0aeeed4>] (cpu_up+0x5c/0x78)
[<c0aeeed4>] (cpu_up+0x5c/0x78) from [<c0aec808>] (store_online+0x44/0x74)
[<c0aec808>] (store_online+0x44/0x74) from [<c03a40f4>] (sysfs_write_file+0x108/0x14c)
[<c03a40f4>] (sysfs_write_file+0x108/0x14c) from [<c03517d4>] (vfs_write+0xd0/0x180)
[<c03517d4>] (vfs_write+0xd0/0x180) from [<c0351ca8>] (SyS_write+0x38/0x68)
[<c0351ca8>] (SyS_write+0x38/0x68) from [<c0205de0>] (ret_fast_syscall+0x0/0x30)

Fix that by taking locks at appropriate places in __cpufreq_add_dev()
as well.

Reported-by: default avatarSaravana Kannan <skannan@codeaurora.org>
Suggested-by: default avatarSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
[rjw: Changelog]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      4e97b631
    • Viresh Kumar's avatar
      cpufreq: Initialize policy before making it available for others to use · 5a7e56a5
      Viresh Kumar authored 
      

Policy must be fully initialized before it is being made available
for use by others. Otherwise cpufreq_cpu_get() would be able to grab
a half initialized policy structure that might not have affected_cpus
(for example) populated. Then, anybody accessing those fields will get
a wrong value and that will lead to unpredictable results.

In order to fix this, do all the necessary initialization before we
make the policy structure available via cpufreq_cpu_get(). That will
guarantee that any code accessing fields of the policy will get
correct data from them.

Reported-by: default avatarSaravana Kannan <skannan@codeaurora.org>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
[rjw: Changelog]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      5a7e56a5
    • Aaron Plattner's avatar
      cpufreq: use cpufreq_cpu_get() to avoid cpufreq_get() race conditions · 999976e0
      Aaron Plattner authored 
      If a module calls cpufreq_get while cpufreq is initializing, it's
possible for it to be called after cpufreq_driver is set but before
cpufreq_cpu_data is written during subsys_interface_register.  This
happens because cpufreq_get doesn't take the cpufreq_driver_lock
around its use of cpufreq_cpu_data.

Fix this by using cpufreq_cpu_get(cpu) to look up the policy rather
than reading it out of cpufreq_cpu_data directly.  cpufreq_cpu_get()
takes the appropriate locks to prevent this race from happening.

Since it's possible for policy to be NULL if the caller passes in an
invalid CPU number or calls the function before cpufreq is initialized,
delete the BUG_ON(!policy) and simply return 0.  Don't try to return
-ENOENT because that's negative and the function returns an unsigned
integer.

References: https://bbs.archlinux.org/viewtopic.php?id=177934


Signed-off-by: default avatarAaron Plattner <aplattner@nvidia.com>
Cc: 3.13+ <stable@vger.kernel.org> # 3.13+
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      999976e0
  5. Mar 03, 2014
  7. Mar 02, 2014
  9. Mar 01, 2014
  11. Feb 28, 2014
    • Steve Capper's avatar
      arm64: mm: Add double logical invert to pte accessors · 84fe6826
      Steve Capper authored 
      

Page table entries on ARM64 are 64 bits, and some pte functions such as
pte_dirty return a bitwise-and of a flag with the pte value. If the
flag to be tested resides in the upper 32 bits of the pte, then we run
into the danger of the result being dropped if downcast.

For example:
	gather_stats(page, md, pte_dirty(*pte), 1);
where pte_dirty(*pte) is downcast to an int.

This patch adds a double logical invert to all the pte_ accessors to
ensure predictable downcasting.

Signed-off-by: default avatarSteve Capper <steve.capper@linaro.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      84fe6826
    • Heinz Mauelshagen's avatar
      dm cache: fix truncation bug when mapping I/O to >2TB fast device · e0d849fa
      Heinz Mauelshagen authored 
      

When remapping a block to the cache's fast device that is larger than
2TB we must not truncate the destination sector to 32bits.  The 32bit
temporary result of from_cblock() was being overflowed in
remap_to_cache() due to the logical left shift.

Use an intermediate 64bit type to store the 32bit from_cblock() result
to fix the overflow.

Signed-off-by: default avatarHeinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
      e0d849fa
    • Jiri Olsa's avatar
      perf tools: Fix strict alias issue for find_first_bit · b39c2a57
      Jiri Olsa authored 
      When compiling perf tool code with gcc 4.4.7 I'm getting
following error:

    CC       util/session.o
  cc1: warnings being treated as errors
  util/session.c: In function ‘perf_session_deliver_event’:
  tools/perf/util/include/linux/bitops.h:109: error: dereferencing pointer ‘p’ does break strict-aliasing rules
  tools/perf/util/include/linux/bitops.h:101: error: dereferencing pointer ‘p’ does break strict-aliasing rules
  util/session.c:697: note: initialized from here
  tools/perf/util/include/linux/bitops.h:101: note: initialized from here
  make[1]: *** [util/session.o] Error 1
  make: *** [util/session.o] Error 2

The aliased types here are u64 and unsigned long pointers, which is safe
for the find_first_bit processing.

This error shows up for me only for gcc 4.4 on 32bit x86, even for
-Wstrict-aliasing=3, while newer gcc are quiet and scream here for
-Wstrict-aliasing={2,1}. Looks like newer gcc changed the rules for
strict alias warnings.

The gcc documentation offers workaround for valid aliasing by using
__may_alias__ attribute:

  http://gcc.gnu.org/onlinedocs/gcc-4.4.0/gcc/Type-Attributes.html



Using this workaround for the find_first_bit function.

Signed-off-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1393434867-20271-1-git-send-email-jolsa@redhat.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      b39c2a57
    • Benjamin Herrenschmidt's avatar
      powerpc/powernv: Fix indirect XSCOM unmangling · e0cf9576
      Benjamin Herrenschmidt authored 
      

We need to unmangle the full address, not just the register
number, and we also need to support the real indirect bit
being set for in-kernel uses.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org> [v3.13]
      e0cf9576
    • Benjamin Herrenschmidt's avatar
      powerpc/powernv: Fix opal_xscom_{read,write} prototype · 2f3f38e4
      Benjamin Herrenschmidt authored 
      

The OPAL firmware functions opal_xscom_read and opal_xscom_write
take a 64-bit argument for the XSCOM (PCB) address in order to
support the indirect mode on P8.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org> [v3.13]
      2f3f38e4
    • Gavin Shan's avatar
      powerpc/powernv: Refactor PHB diag-data dump · af87d2fe
      Gavin Shan authored 
      

As Ben suggested, the patch prints PHB diag-data with multiple
fields in one line and omits the line if the fields of that
line are all zero.

With the patch applied, the PHB3 diag-data dump looks like:

PHB3 PHB#3 Diag-data (Version: 1)

  brdgCtl:     00000002
  RootSts:     0000000f 00400000 b0830008 00100147 00002000
  nFir:        0000000000000000 0030006e00000000 0000000000000000
  PhbSts:      0000001c00000000 0000000000000000
  Lem:         0000000000100000 42498e327f502eae 0000000000000000
  InAErr:      8000000000000000 8000000000000000 0402030000000000 0000000000000000
  PE[  8] A/B: 8480002b00000000 8000000000000000

[ The current diag data is so big that it overflows the printk
  buffer pretty quickly in cases when we get a handful of errors
  at once which can happen. --BenH
]

Signed-off-by: default avatarGavin Shan <shangw@linux.vnet.ibm.com>
CC: <stable@vger.kernel.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      af87d2fe