linux-toradex.git/drivers/acpi, branch v3.12.29

ACPI / cpuidle: fix deadlock between cpuidle_lock and cpu_hotplug.lock

2014-09-17T14:55:09+00:00

commit 6726655dfdd2dc60c035c690d9f10cb69d7ea075 upstream.

There is a following AB-BA dependency between cpu_hotplug.lock and
cpuidle_lock:

1) cpu_hotplug.lock -> cpuidle_lock
enable_nonboot_cpus()
 _cpu_up()
  cpu_hotplug_begin()
   LOCK(cpu_hotplug.lock)
 cpu_notify()
  ...
  acpi_processor_hotplug()
   cpuidle_pause_and_lock()
    LOCK(cpuidle_lock)

2) cpuidle_lock -> cpu_hotplug.lock
acpi_os_execute_deferred() workqueue
 ...
 acpi_processor_cst_has_changed()
  cpuidle_pause_and_lock()
   LOCK(cpuidle_lock)
  get_online_cpus()
   LOCK(cpu_hotplug.lock)

Fix this by reversing the order acpi_processor_cst_has_changed() does
thigs -- let it first execute the protection against CPU hotplug by
calling get_online_cpus() and obtain the cpuidle lock only after that (and
perform the symmentric change when allowing CPUs hotplug again and
dropping cpuidle lock).

Spotted by lockdep.

Signed-off-by: Jiri Kosina 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

ACPICA: Utilities: Fix memory leak in acpi_ut_copy_iobject_to_iobject

2014-09-17T14:55:09+00:00

commit 8aa5e56eeb61a099ea6519eb30ee399e1bc043ce upstream.

Adds return status check on copy routines to delete the allocated destination
object if either copy fails. Reported by Colin Ian King on bugs.acpica.org,
Bug 1087.
The last applicable commit:
 Commit: 3371c19c294a4cb3649aa4e84606be8a1d999e61
 Subject: ACPICA: Remove ACPI_GET_OBJECT_TYPE macro

Link: https://bugs.acpica.org/show_bug.cgi?id=1087
Reported-by: Colin Ian King 
Signed-off-by: David E. Box 
Signed-off-by: Bob Moore 
Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

ACPI / resources: only reject zero length resources based at address zero

2014-07-28T07:12:21+00:00

commit 867f9d463b82462793ea4610e748be0b04b37fc7 upstream.

The recently merged change (in v3.14-rc6) to ACPI resource detection
(below) causes all zero length ACPI resources to be elided from the
table:

  commit b355cee88e3b1a193f0e9a81db810f6f83ad728b
  Author: Zhang Rui 
  Date:   Thu Feb 27 11:37:15 2014 +0800

    ACPI / resources: ignore invalid ACPI device resources

This change has caused a regression in (at least) serial port detection
for a number of machines (see LP#1313981 [1]).  These seem to represent
their IO regions (presumably incorrectly) as a zero length region.
Reverting the above commit restores these serial devices.

Only elide zero length resources which lie at address 0.

Fixes: b355cee88e3b (ACPI / resources: ignore invalid ACPI device resources)
Signed-off-by: Andy Whitcroft 
Acked-by: Zhang Rui 
Cc: 3.14+  # 3.14+
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

ACPI / battery: Retry to get battery information if failed during probing

2014-07-18T13:51:31+00:00

commit 75646e758a0ecbed5024454507d5be5b9ea9dcbf upstream.

Some machines (eg. Lenovo Z480) ECs are not stable during boot up
and causes battery driver fails to be loaded due to failure of getting
battery information from EC sometimes. After several retries, the
operation will work. This patch is to retry to get battery information 5
times if the first try fails.

[ backport to 3.14.5: removed second parameter in acpi_battery_update(),
introduced by the commit 9e50bc14a7f58b5d8a55973b2d69355852ae2dae (ACPI /
battery: Accelerate battery resume callback)]

[naszar : backport to 3.14.5]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=75581
Reported-and-tested-by: naszar 
Cc: All applicable 
Signed-off-by: Lan Tianyu 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

ACPI / EC: Fix race condition in ec_transaction_completed()

2014-07-18T13:51:19+00:00

commit c0d653412fc8450370167a3268b78fc772ff9c87 upstream.

There is a race condition in ec_transaction_completed().

When ec_transaction_completed() is called in the GPE handler, it could
return true because of (ec->curr == NULL). Then the wake_up() invocation
could complete the next command unexpectedly since there is no lock between
the 2 invocations. With the previous cleanup, the IBF=0 waiter race need
not be handled any more. It's now safe to return a flag from
advance_condition() to indicate the requirement of wakeup, the flag is
returned from a locked context.

The ec_transaction_completed() is now only invoked by the ec_poll() where
the ec->curr is ensured to be different from NULL.

After cleaning up, the EVT_SCI=1 check should be moved out of the wakeup
condition so that an EVT_SCI raised with (ec->curr == NULL) can trigger a
QR_SC command.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911
Reported-and-tested-by: Gareth Williams 
Reported-and-tested-by: Hans de Goede 
Reported-by: Barton Xu 
Tested-by: Steffen Weber 
Tested-by: Arthur Chen 
Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

ACPI / EC: Remove duplicated ec_wait_ibf0() waiter

2014-07-18T13:51:19+00:00

commit 9b80f0f73ae1583c22325ede341c74195847618c upstream.

After we've added the first command byte write into advance_transaction(),
the IBF=0 waiter is duplicated with the command completion waiter
implemented in the ec_poll() because:
   If IBF=1 blocked the first command byte write invoked in the task
   context ec_poll(), it would be kicked off upon IBF=0 interrupt or timed
   out and retried again in the task context.

Remove this seperate and duplicate IBF=0 waiter.  By doing so we can
reduce the overall number of times to access the EC_SC(R) status
register.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911
Reported-and-tested-by: Gareth Williams 
Reported-and-tested-by: Hans de Goede 
Reported-by: Barton Xu 
Tested-by: Steffen Weber 
Tested-by: Arthur Chen 
Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

ACPI / EC: Add asynchronous command byte write support

2014-07-18T13:51:19+00:00

commit f92fca0060fc4dc9227342d0072d75df98c1e5a5 upstream.

Move the first command byte write into advance_transaction() so that all
EC register accesses that can affect the command processing state machine
can happen in this asynchronous state machine advancement function.

The advance_transaction() function then can be a complete implementation
of an asyncrhonous transaction for a single command so that:
 1. The first command byte can be written in the interrupt context;
 2. The command completion waiter can also be used to wait the first command
    byte's timeout;
 3. In BURST mode, the follow-up command bytes can be written in the
    interrupt context directly, so that it doesn't need to return to the
    task context. Returning to the task context reduces the throughput of
    the BURST mode and in the worst cases where the system workload is very
    high, this leads to the hardware driven automatic BURST mode exit.

In order not to increase memory consumption, convert 'done' into 'flags'
to contain multiple indications:
 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition,
    indicating the completion of the command transaction.
 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first
    command byte. A new command can utilize this flag to compete for the
    right of accessing the underlying hardware. There is a follow-up bug
    fix that has utilized this new flag.

The 2 flags are important because it also reflects a key concept of IO
programs' design used in the system softwares. Normally an IO program
running in the kernel should first be implemented in the asynchronous way.
And the 2 flags are the most common way to implement its synchronous
operations on top of the asynchronous operations:
1. POLL: This flag can be used to block until the asynchronous operations
         can happen.
2. COMPLETE: This flag can be used to block until the asynchronous
             operations have completed.
By constructing code cleanly in this way, many difficult problems can be
solved smoothly.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911
Reported-and-tested-by: Gareth Williams 
Reported-and-tested-by: Hans de Goede 
Reported-by: Barton Xu 
Tested-by: Steffen Weber 
Tested-by: Arthur Chen 
Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

ACPI / EC: Avoid race condition related to advance_transaction()

2014-07-18T13:51:18+00:00

commit 66b42b78bc1e816f92b662e8888c89195e4199e1 upstream.

The advance_transaction() will be invoked from the IRQ context GPE handler
and the task context ec_poll(). The handling of this function is locked so
that the EC state machine are ensured to be advanced sequentially.

But there is a problem. Before invoking advance_transaction(), EC_SC(R) is
read. Then for advance_transaction(), there could be race condition around
the lock from both contexts. The first one reading the register could fail
this race and when it passes the stale register value to the state machine
advancement code, the hardware condition is totally different from when
the register is read. And the hardware accesses determined from the wrong
hardware status can break the EC state machine. And there could be cases
that the functionalities of the platform firmware are seriously affected.
For example:
 1. When 2 EC_DATA(W) writes compete the IBF=0, the 2nd EC_DATA(W) write may
    be invalid due to IBF=1 after the 1st EC_DATA(W) write. Then the
    hardware will either refuse to respond a next EC_SC(W) write of the next
    command or discard the current WR_EC command when it receives a EC_SC(W)
    write of the next command.
 2. When 1 EC_SC(W) write and 1 EC_DATA(W) write compete the IBF=0, the
    EC_DATA(W) write may be invalid due to IBF=1 after the EC_SC(W) write.
    The next EC_DATA(R) could never be responded by the hardware. This is
    the root cause of the reported issue.

Fix this issue by moving the EC_SC(R) access into the lock so that we can
ensure that the state machine is advanced consistently.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911
Reported-and-tested-by: Gareth Williams 
Reported-and-tested-by: Hans de Goede 
Reported-by: Barton Xu 
Tested-by: Steffen Weber 
Tested-by: Arthur Chen 
Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

ACPI: Fix conflict between customized DSDT and DSDT local copy

2014-07-02T10:06:25+00:00

commit 73577d1df8e1f31f6b1a5eebcdbc334eb0330e47 upstream.

This patch fixes the following issue:
If DSDT is customized, no local DSDT copy is needed.

References: https://bugzilla.kernel.org/show_bug.cgi?id=69711
Signed-off-by: Enrico Etxe Arte 
Signed-off-by: Lv Zheng 
[rjw: Subject]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

ACPICA: utstring: Check array index bound before use.

2014-07-02T10:06:24+00:00

commit 5d42b0fa25df7ef2f575107597c1aaebe2407d10 upstream.

ACPICA BZ 1077. David Binderman.

References: https://bugs.acpica.org/show_bug.cgi?id=1077
Signed-off-by: David Binderman 
Signed-off-by: Bob Moore 
Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby