There is platform refusing to respond QR_EC when SCI_EVT isn't set
which is Acer Aspire V5-573G.

By disallowing QR_EC to be issued before the previous one has been
completed we are able to reduce the possibilities to trigger issues on
such platforms.

Note that this fix can only reduce the occurrence rate of this issue, but
this issue may still occur when such a platform doesn't clear SCI_EVT
before or immediately after completing the previous QR_EC transaction.
This patch cannot fix the CLEAR_ON_RESUME quirk which also relies on
the assumption that the platforms are able to respond even when SCI_EVT
isn't set.

But this patch is still useful as it can help to reduce the number of
scheduled QR_EC work items.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=82611Reported-and-tested-by: NAlexander Mezin <mezin.alexander@gmail.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Cc: 3.16+ <stable@vger.kernel.org> # 3.16+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is a platform refusing to respond QR_EC when SCI_EVT isn't set
(Acer Aspire V5-573G).

Currently, we rely on the behaviour that the EC firmware can respond
something (for example, 0x00 to indicate "no outstanding events") to
QR_EC even when SCI_EVT is not set, but the reporter has complained
about AC/battery pluging/unpluging and video brightness change delay
on that platform.

This is because the work item that has issued QR_EC has to wait until
timeout in this case, and the _Qxx method evaluation work item queued
after QR_EC one is delayed.

It sounds reasonable to fix this issue by:
 1. Implementing SCI_EVT sanity check before issuing QR_EC in the EC
    driver's main state machine.
 2. Moving QR_EC issuing out of the work queue used by _Qxx evaluation
    to a seperate IRQ handling thread.

This patch fixes this issue using solution 1.

By disallowing QR_EC to be issued when SCI_EVT isn't set, we are able to
handle such platform in the EC driver's main state machine. This patch
enhances the state machine in this way to survive with such malfunctioning
EC firmware.

Note that this patch can also fix CLEAR_ON_RESUME quirk which also relies
on the assumption that the platforms are able to respond even when SCI_EVT
isn't set.

Fixes: c0d65341 ACPI / EC: Fix race condition in ec_transaction_completed()
Link: https://bugzilla.kernel.org/show_bug.cgi?id=82611Reported-and-tested-by: NAlexander Mezin <mezin.alexander@gmail.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Cc: 3.16+ <stable@vger.kernel.org> # 3.16+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Smatch detected two memory leaks on saved_ec:

drivers/acpi/ec.c:1070 acpi_ec_ecdt_probe() warn: possible
  memory leak of 'saved_ec'
drivers/acpi/ec.c:1109 acpi_ec_ecdt_probe() warn: possible
  memory leak of 'saved_ec'

Free saved_ec on these two error exit paths to stop the memory
leak.  Note that saved_ec maybe null, but kfree on null is allowed.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Acked-by: NLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Developers really don't need to translate EC_SC(R) in mind as long as the
field details are decoded in the debugging message.
Tested-by: NGareth Williams <gareth@garethwilliams.me.uk>
Tested-by: NSteffen Weber <steffen.weber@gmail.com>
Tested-by: NHans de Goede <jwrdegoede@fedoraproject.org>
Tested-by: NArthur Chen <axchen@nvidia.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The bug fixes and asynchronous improvements have been done to the EC driver
by the previous commits. This patch increases the revision to 2.2 to
indicate the behavior differences between the old and the new drivers. The
copyright/authorship notices are also updated.
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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=59911Reported-and-tested-by: NGareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: NHans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: NBarton Xu <tank.xuhan@gmail.com>
Tested-by: NSteffen Weber <steffen.weber@gmail.com>
Tested-by: NArthur Chen <axchen@nvidia.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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=59911Reported-and-tested-by: NGareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: NHans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: NBarton Xu <tank.xuhan@gmail.com>
Tested-by: NSteffen Weber <steffen.weber@gmail.com>
Tested-by: NArthur Chen <axchen@nvidia.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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=59911Reported-and-tested-by: NGareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: NHans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: NBarton Xu <tank.xuhan@gmail.com>
Tested-by: NSteffen Weber <steffen.weber@gmail.com>
Tested-by: NArthur Chen <axchen@nvidia.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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=59911Reported-and-tested-by: NGareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: NHans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: NBarton Xu <tank.xuhan@gmail.com>
Tested-by: NSteffen Weber <steffen.weber@gmail.com>
Tested-by: NArthur Chen <axchen@nvidia.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Address a regression caused by commit ad332c8a:
(ACPI / EC: Clear stale EC events on Samsung systems)

After the earlier patch, there was found to be a race condition on some
earlier Samsung systems (N150/N210/N220). The function acpi_ec_clear was
sometimes discarding a new EC event before its GPE was triggered by the
system. In the case of these systems, this meant that the "lid open"
event was not registered on resume if that was the cause of the wake,
leading to problems when attempting to close the lid to suspend again.

After testing on a number of Samsung systems, both those affected by the
previous EC bug and those affected by the race condition, it seemed that
the best course of action was to process rather than discard the events.
On Samsung systems which accumulate stale EC events, there does not seem
to be any adverse side-effects of running the associated _Q methods.

This patch adds an argument to the static function acpi_ec_sync_query so
that it may be used within the acpi_ec_clear loop in place of
acpi_ec_query_unlocked which was used previously.

With thanks to Stefan Biereigel for reporting the issue, and for all the
people who helped test the new patch on affected systems.

Fixes: ad332c8a (ACPI / EC: Clear stale EC events on Samsung systems)
References: https://lkml.kernel.org/r/532FE3B2.9060808@biereigel-wb.de
References: https://bugzilla.kernel.org/show_bug.cgi?id=44161#c173Reported-by: NStefan Biereigel <stefan@biereigel.de>
Signed-off-by: NKieran Clancy <clancy.kieran@gmail.com>
Tested-by: NStefan Biereigel <stefan@biereigel.de>
Tested-by: NDennis Jansen <dennis.jansen@web.de>
Tested-by: NNicolas Porcel <nicolasporcel06@gmail.com>
Tested-by: NMaurizio D'Addona <mauritiusdadd@gmail.com>
Tested-by: NJuan Manuel Cabo <juanmanuel.cabo@gmail.com>
Tested-by: NGiannis Koutsou <giannis.koutsou@gmail.com>
Tested-by: NKieran Clancy <clancy.kieran@gmail.com>
Cc: 3.14+ <stable@vger.kernel.org> # 3.14+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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=126801Suggested-by: NJuan Manuel Cabo <juanmanuel.cabo@gmail.com>
Signed-off-by: NKieran Clancy <clancy.kieran@gmail.com>
Reviewed-by: NLan Tianyu <tianyu.lan@intel.com>
Reviewed-by: NDennis Jansen <dennis.jansen@web.de>
Tested-by: NKieran Clancy <clancy.kieran@gmail.com>
Tested-by: NJuan Manuel Cabo <juanmanuel.cabo@gmail.com>
Tested-by: NDennis Jansen <dennis.jansen@web.de>
Tested-by: NMaurizio D'Addona <mauritiusdadd@gmail.com>
Tested-by: NSan Zamoyski <san@plusnet.pl>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Adds the prototype declarations of functions acpi_ec_add_query_handler()
and acpi_ec_remove_query_handler() in header file internal.h and removes
unused functions ec_burst_enable() and ec_burst_disable() in ec.c.

This eliminates the following warnings in ec.c:
drivers/acpi/ec.c:393:5: warning: no previous prototype for ‘ec_burst_enable’ [-Wmissing-prototypes]
drivers/acpi/ec.c:402:5: warning: no previous prototype for ‘ec_burst_disable’ [-Wmissing-prototypes]
drivers/acpi/ec.c:531:5: warning: no previous prototype for ‘acpi_ec_add_query_handler’ [-Wmissing-prototypes]
drivers/acpi/ec.c:552:6: warning: no previous prototype for ‘acpi_ec_remove_query_handler’ [-Wmissing-prototypes]
Signed-off-by: NRashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Adjust the order of disabling the EC GPE and removing its handler to
avoid unhandled events.
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
[rjw: Changelog]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Replace direct inclusions of <acpi/acpi.h>, <acpi/acpi_bus.h> and
<acpi/acpi_drivers.h>, which are incorrect, with <linux/acpi.h>
inclusions and remove some inclusions of those files that aren't
necessary.

First of all, <acpi/acpi.h>, <acpi/acpi_bus.h> and <acpi/acpi_drivers.h>
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,
<linux/acpi.h> 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 <acpi/acpi_bus.h> be included
prior to <acpi/acpi_drivers.h> so that the acpi_pci_root declarations the
latter depends on are always there.  And <acpi/acpi.h> 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
<linux/acpi.h> as appropriate.
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> (drivers/pci stuff)
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> (Xen stuff)
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

A bug was introduced by commit b76b51ba ('ACPI / EC: Add more debug
info and trivial code cleanup') that erroneously caused the struct member
to be accessed before acquiring the required lock.  This change fixes
it by ensuring the lock acquisition is done first.

Found by Aaron Durbin <adurbin@chromium.org>

Fixes: b76b51ba ('ACPI / EC: Add more debug info and trivial code cleanup')
References: http://crbug.com/319019Signed-off-by: NPuneet Kumar <puneetster@chromium.org>
Reviewed-by: NAaron Durbin <adurbin@chromium.org>
[olof: Commit message reworded a bit]
Signed-off-by: NOlof Johansson <olof@lixom.net>
Cc: 3.8+ <stable@vger.kernel.org> # 3.8+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch is to convert all printks in the ec driver to pr_debug/info/err
and define pr_fmt macro to replace PREFIX.
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The ECDT of ASUSTEK L4R doesn't provide correct command and data
I/O ports.  The DSDT provides the correct information instead.

For this reason, add this machine to quirk list for ECDT validation
and use the EC information from the DSDT.

[rjw: Changelog]
References: https://bugzilla.kernel.org/show_bug.cgi?id=60765Reported-and-tested-by: NDaniele Esposti <expo@expobrain.net>
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Cc: All <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

__initdata should be placed between the variable name and equal
sign for the variable to be placed in the intended section.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Introduce helper function acpi_has_method() and use it in a number
of places to simplify code.

[rjw: Changelog]
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

HP Folio 13's BIOS defines CMOS RTC Operation Region and the EC's
_REG method will access that region.  To allow the CMOS RTC region
handler to be installed before the EC _REG method is first invoked,
add ec_skip_dsdt_scan() as HP Folio 13's callback to ec_dmi_table.

References: https://bugzilla.kernel.org/show_bug.cgi?id=54621Reported-and-tested-by: NStefan Nagy <public@stefan-nagy.at>
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Cc: 3.9+ <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The EC driver works abnormally with IBF flag always set.
IBF means "The host has written a byte of data to the command
or data port, but the embedded controller has not yet read it".
If IBF is set in the EC status and not cleared, this will cause
all subsequent EC requests to fail with a timeout error.

Change the EC driver so that it doesn't refuse to restart a
transaction if IBF is set in the status.  Also increase the
number of transaction restarts to 5, as it turns out that 2
is not sufficient in some cases.

This bug happens on several different machines (Asus V1S,
Dell Latitude E6530, Samsung R719, Acer Aspire 5930G,
Sony Vaio SR19VN and others).

[rjw: Changelog]
References: https://bugzilla.kernel.org/show_bug.cgi?id=14733
References: https://bugzilla.kernel.org/show_bug.cgi?id=15560
References: https://bugzilla.kernel.org/show_bug.cgi?id=15946
References: https://bugzilla.kernel.org/show_bug.cgi?id=42945
References: https://bugzilla.kernel.org/show_bug.cgi?id=48221Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Cc: All <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NJiang Liu <jiang.liu@huawei.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>

Currently when advance_transaction() is called in EC interrupt handler,
if there is nothing driver can do with the interrupt, it will be taken
as a false one.

But this is not always true, as there may be a SCI EC interrupt fired
during normal read/write operation, which should not be counted as a
false one. This patch fixes the problem.
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add more debug info for EC transaction debugging, like the interrupt
status register value, the detail info of a EC transaction.
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Current member names for mutex/spinlock are a little confusing.

Change the
{
	struct mutex lock;
	spinlock_t curr_lock;
}
to
{
	struct mutex mutex;
	spinlock_t lock;
}

So that the code is cleaner and easier to read.
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

By enlarging the GPE storm threshold back to 20, that laptop's
EC works fine with interrupt mode instead of polling mode.

https://bugzilla.kernel.org/show_bug.cgi?id=45151Reported-and-Tested-by: NFrancesco <trentini@dei.unipd.it>
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>
cc: stable@vger.kernel.org

The Linux EC driver includes a mechanism to detect GPE storms,
and switch from interrupt-mode to polling mode.  However, polling
mode sometimes doesn't work, so the workaround is problematic.
Also, different systems seem to need the threshold for detecting
the GPE storm at different levels.

ACPI_EC_STORM_THRESHOLD was initially 20 when it's created, and
was changed to 8 in 2.6.28 commit 06cf7d3c "ACPI: EC: lower interrupt storm
threshold" to fix kernel bug 11892 by forcing the laptop in that bug to
work in polling mode. However in bug 45151, it works fine in interrupt
mode if we lift the threshold back to 20.

This patch makes the threshold a module parameter so that user has a
flexible option to debug/workaround this issue.

The default is unchanged.

This is also a preparation patch to fix specific systems:
	https://bugzilla.kernel.org/show_bug.cgi?id=45151Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>
cc: stable@vger.kernel.org

WARN() is not supposed to have side effects, so move the request_regions
outside.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

toshiba_acpi needs to execute an AML method within the EC namespace
to make hotkeys work on some platforms. Provide an interface to
allow it to easily get a handle to the EC namespace for this purpose.
Signed-off-by: NSeth Forshee <seth.forshee@canonical.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

ec->handle is set in ec_parse_device(), so don't bother to set it again.
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Enable MSI workaround for Quanta laptops.
https://bugzilla.kernel.org/show_bug.cgi?id=20242Tested-by: NJan-Matthias Braun <jan_braun@gmx.net>
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Commit 0adf3c74 introduced a regression
by making the ECDT validation test for ASUS hardware more restrictive.
The previous test used the dmi_name_in_vendors function which searches
a number of DMI fields, while the new test checked only the BIOS
vendor, which is known to not match on an ASUS F5GL laptop which
requires ECDT validation.

Add a rule to ec_dmi_table based on an alternative DMI pattern for
ASUS hardware as found elsewhere in the kernel.
Signed-off-by: NPeter Collingbourne <peter@pcc.me.uk>
Signed-off-by: NLen Brown <len.brown@intel.com>

static void acpi_ec_gpe_query(void *ec_cxt);
-> The function is right above this declaration -> not needed.

poll_force is also not used, cleaned up in ec.c and its users:
compal-laptop and msi-laptop.
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

This feature provides an automatic device notification for wake devices
when a wakeup GPE occurs and there is no corresponding GPE method or
handler. Rather than ignoring such a GPE, an implicit AML Notify
operation is performed on the parent device object.
This feature is not part of the ACPI specification and is provided for
Windows compatibility only.
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The new GPE handler callback has 2 additional parameters, gpe_device and
gpe_number.

typedef
u32 (*acpi_gpe_handler) (acpi_handle gpe_device, u32 gpe_number, void *context);
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

http://bugzilla.kernel.org/show_bug.cgi?id=15418Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
cc: stable@kernel.org
Signed-off-by: NLen Brown <len.brown@intel.com>

Here and then there show up machines which need higher timeout values.
Finding this on affected machines can be cumbersome, because
ACPI_EC_DELAY is a compile option -> make it configurable via boot param.

This can even be provided writable at runtime via:
/sys/modules/acpi/parameters/ec_delay

Known machines where this helps:
Some HP machines where for whatever reasons specific EC accesses take
very long at resume from S3 (in _WAK function).
The AE_TIME error is passed upwards and the ACPI interpreter will
not execute the rest of the _WAK function which results in not properly
initialized devices/variables with different side-effects.

Afaik, on some MSI machines this helped as well.

If this param is needed there probably are underlying problems like:
  - EC firmware bug
  - A kernel EC driver bug
  - An ACPI interpreter behavior (e.g. timings when specific
    EC accesses happen and how) which the EC does not like
  - ...
which should get evaluated further, but often are nasty or
impossible to fix from OS side.
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

which will result in a harmless but ugly WARN message on
some machines.
Signed-off-by: NThomas Renninger <trenn@suse.de>
CC: mjg59@srcf.ucam.org
CC: platform-driver-x86@vger.kernel.org
CC: linux-acpi@vger.kernel.org
CC: astarikovskiy@suse.de
CC: akpm@linux-foundation.org
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Formerly these have been exposed through /proc/..
Better register them where all IO ports should get registered
and scream loud if someone else claims to use them.

EC data and command port typically should show up like this
then:
...
  0060-0060 : keyboard
  0062-0062 : EC data
  0064-0064 : keyboard
  0066-0066 : EC command
  0070-0071 : rtc0
...
Signed-off-by: NThomas Renninger <trenn@suse.de>

CC: Alexey Starikovskiy <astarikovskiy@suse.de>
CC: Len Brown <lenb@kernel.org>
CC: linux-kernel@vger.kernel.org
CC: linux-acpi@vger.kernel.org
CC: Bjorn Helgaas <bjorn.helgaas@hp.com>
CC: platform-driver-x86@vger.kernel.org
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

This patch provides the same information through debugfs, which previously was
provided through /proc/acpi/embedded_controller/*/info

This is the gpe the EC is connected to and whether the global lock
gets used.
The io ports used are added to /proc/ioports in another patch.
Beside the fact that /proc/acpi is deprecated for quite some time,
this info is not needed for applications and thus can be moved
to debugfs instead of a public interface like /sys.
Signed-off-by: NThomas Renninger <trenn@suse.de>

CC: Alexey Starikovskiy <astarikovskiy@suse.de>
CC: Len Brown <lenb@kernel.org>
CC: linux-kernel@vger.kernel.org
CC: linux-acpi@vger.kernel.org
CC: Bjorn Helgaas <bjorn.helgaas@hp.com>
CC: platform-driver-x86@vger.kernel.org
Signed-off-by: NMatthew Garrett <mjg@redhat.com>