linux-toradex.git/drivers/acpi/sbshc.c, branch v4.17

ACPI: sbshc: remove raw pointer from printk() message

2018-02-08T08:50:08+00:00

There's no need to be printing a raw kernel pointer to the kernel log at
every boot.  So just remove it, and change the whole message to use the
correct dev_info() call at the same time.

Reported-by: Wang Qize 
Cc: All applicable 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Rafael J. Wysocki

Revert "ACPI / SBS: Add 5 us delay to fix SBS hangs on MacBook"

2015-11-16T22:26:45+00:00

Revert commit 3349fb64b292 (ACPI / SBS: Add 5 us delay to fix SBS
hangs on MacBook), since the delay introduced by it is not necessary
any more after commit add68d6aa9e2 (ACPI / SMBus: Fix boot stalls /
high CPU caused by reentrant code).

Signed-off-by: Chris Bainbridge 
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki

ACPI / SMBus: Fix boot stalls / high CPU caused by reentrant code

2015-11-16T22:23:45+00:00

In the SBS initialisation, a reentrant call to wait_event_timeout()
causes an intermittent boot stall of several minutes usually following
the "Switching to clocksource tsc" message. Another symptom of this bug
is high CPU usage from programs (Firefox, upowerd) querying the battery
state. This is caused by:

 1. drivers/acpi/sbshc.c wait_transaction_complete() calls
    wait_event_timeout():

 	if (wait_event_timeout(hc->wait, smb_check_done(hc),
 			       msecs_to_jiffies(timeout)))

 2. ___wait_event sets task state to uninterruptible

 3. ___wait_event calls the "condition" smb_check_done()

 4. smb_check_done (sbshc.c) calls through to ec_read() in
    drivers/acpi/ec.c

 5. ec_guard() is reached which calls wait_event_timeout()

 	if (wait_event_timeout(ec->wait,
 			       ec_transaction_completed(ec),
 			       guard))

    ie. wait_event_timeout() is being called again inside evaluation of
    the previous wait_event_timeout() condition

 5. The EC IRQ handler calls wake_up() and wakes up the sleeping task in
    ec_guard()

 6. The task is now in state running even though the wait "condition" is
    still being evaluated

 7. The "condition" check returns false so ___wait_event calls
    schedule_timeout()

 8. Since the task state is running, the scheduler immediately schedules
    it again

 9. This loop usually repeats for around 250 seconds even though the
    original wait_event_timeout was only 1000ms.

    The timeout is incorrect because each call to schedule_timeout()
    usually returns immediately, taking less than 1ms, so the jiffies
    timeout counter is not decremented. The task is now stuck in a
    running state, and so is highly likely to be immediately
    rescheduled, which takes less than a jiffy. The loop will never exit
    if all schedule_timeout() calls take less than a jiffy.

Fix this by replacing SMBus reads in the wait_event_timeout condition
with checks of a boolean value that is updated by the EC query handler.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=107191
Link: https://lkml.org/lkml/2015/11/6/776
Signed-off-by: Chris Bainbridge 
Signed-off-by: Rafael J. Wysocki

ACPI / SBS: Add 5 us delay to fix SBS hangs on MacBook

2015-04-30T21:18:11+00:00

Commit 7bc5a2bad0b8 'ACPI: Support _OSI("Darwin") correctly' caused
the MacBook firmware to expose the SBS, resulting in intermittent
hangs of several minutes on boot, and failure to detect or report
the battery.  Fix this by adding a 5 us delay to the start of each
SMBUS transaction.  This timing is the result of experimentation -
hangs were observed with 3 us but never with 5 us.

Fixes: 7bc5a2bad0b8 'ACPI: Support _OSI("Darwin") correctly'
Link: https://bugzilla.kernel.org/show_bug.cgi?id=94651
Signed-off-by: Chris Bainbridge 
Cc: 3.18+  # 3.18+
[ rjw: Subject and changelog ]
Signed-off-by: Rafael J. Wysocki

ACPI: Clean up inclusions of ACPI header files

2013-12-07T00:03:14+00:00

Replace direct inclusions of ,  and
, which are incorrect, with 
inclusions and remove some inclusions of those files that aren't
necessary.

First of all, ,  and 
should not be included directly from any files that are built for
CONFIG_ACPI unset, because that generally leads to build warnings about
undefined symbols in !CONFIG_ACPI builds.  For CONFIG_ACPI set,
 includes those files and for CONFIG_ACPI unset it
provides stub ACPI symbols to be used in that case.

Second, there are ordering dependencies between those files that always
have to be met.  Namely, it is required that  be included
prior to  so that the acpi_pci_root declarations the
latter depends on are always there.  And  which provides
basic ACPICA type declarations should always be included prior to any other
ACPI headers in CONFIG_ACPI builds.  That also is taken care of including
 as appropriate.

Signed-off-by: Lv Zheng 
Cc: Greg Kroah-Hartman 
Cc: Matthew Garrett 
Cc: Tony Luck 
Cc: "H. Peter Anvin" 
Acked-by: Bjorn Helgaas  (drivers/pci stuff)
Acked-by: Konrad Rzeszutek Wilk  (Xen stuff)
Signed-off-by: Rafael J. Wysocki

ACPI: Remove useless type argument of driver .remove() operation

2013-01-25T23:37:24+00:00

The second argument of ACPI driver .remove() operation is only used
by the ACPI processor driver and the value passed to that driver
through it is always available from the given struct acpi_device
object's removal_type field.  For this reason, the second ACPI driver
.remove() argument is in fact useless, so drop it.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Jiang Liu 
Acked-by: Toshi Kani 
Acked-by: Yinghai Lu

ACPI/sbshc: convert to module_acpi_driver()

2012-09-21T17:39:40+00:00

Signed-off-by: Mika Westerberg 
Signed-off-by: Len Brown

acpi: add module.h to files implicitly using/relying on it.

2011-10-31T23:30:32+00:00

These files are using standard module API things like MODULE_AUTHOR
etc. and so should not be relying on an implicit presence of the
module.h header.

Signed-off-by: Paul Gortmaker

sbshc: acpi_device_class "smbus_host_controller" too long

2010-05-06T06:38:25+00:00

acpi_device_class can only be 19 characters and a NULL terminator.

With the current name we get a buffer overflow in acpi_smbus_hc_add()
when we do:
	strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);

Signed-off-by: Dan Carpenter 
Cc: Alexey Starikovskiy 
Signed-off-by: Andrew Morton 
Signed-off-by: Len Brown

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32+00:00

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo 
Guess-its-ok-by: Christoph Lameter 
Cc: Ingo Molnar 
Cc: Lee Schermerhorn