<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/acpi/internal.h, branch v6.5</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge branches 'acpi-bus' and 'acpi-scan'</title>
<updated>2023-07-06T17:24:06+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2023-07-06T17:24:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2e178ee13b02d95c7380f6a21149de535ccdfc7f'/>
<id>2e178ee13b02d95c7380f6a21149de535ccdfc7f</id>
<content type='text'>
Merge additional ACPI device enumeration code changes for 6.5-rc1.

 - Make acpi_companion_match() return a const pointer and update its
   callers accordingly (Andy Shevchenko).

 - Move the extern declaration of the acpi_root variable to a header
   file so as to address a compiler warning (Andy Shevchenko).

 - Address compiler warnings in the ACPI device enumeration code by
   adding a missing header file include to it (Ben Dooks).

 - Refine the SMB0001 quirk in the ACPI device enumeration code so as to
   address an i2c-scmi driver regression (Andy Shevchenko).

 - Clean up two pieces of the ACPI device enumeration code (Andy
   Shevchenko).

* acpi-bus:
  ACPI: bus: Constify acpi_companion_match() returned value

* acpi-scan:
  ACPI: scan: Use the acpi_match_acpi_device() helper
  ACPI: platform: Move SMB0001 HID to the header and reuse
  ACPI: platform: Ignore SMB0001 only when it has resources
  ACPI: bus: Introduce acpi_match_acpi_device() helper
  ACPI: scan: fix undeclared variable warnings by including sleep.h
  ACPI: scan: Move acpi_root to internal header
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge additional ACPI device enumeration code changes for 6.5-rc1.

 - Make acpi_companion_match() return a const pointer and update its
   callers accordingly (Andy Shevchenko).

 - Move the extern declaration of the acpi_root variable to a header
   file so as to address a compiler warning (Andy Shevchenko).

 - Address compiler warnings in the ACPI device enumeration code by
   adding a missing header file include to it (Ben Dooks).

 - Refine the SMB0001 quirk in the ACPI device enumeration code so as to
   address an i2c-scmi driver regression (Andy Shevchenko).

 - Clean up two pieces of the ACPI device enumeration code (Andy
   Shevchenko).

* acpi-bus:
  ACPI: bus: Constify acpi_companion_match() returned value

* acpi-scan:
  ACPI: scan: Use the acpi_match_acpi_device() helper
  ACPI: platform: Move SMB0001 HID to the header and reuse
  ACPI: platform: Ignore SMB0001 only when it has resources
  ACPI: bus: Introduce acpi_match_acpi_device() helper
  ACPI: scan: fix undeclared variable warnings by including sleep.h
  ACPI: scan: Move acpi_root to internal header
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: bus: Constify acpi_companion_match() returned value</title>
<updated>2023-06-29T09:40:55+00:00</updated>
<author>
<name>Andy Shevchenko</name>
<email>andriy.shevchenko@linux.intel.com</email>
</author>
<published>2023-06-26T11:00:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=86fca926c042138c7defc94e1b55b5f29ca4fa13'/>
<id>86fca926c042138c7defc94e1b55b5f29ca4fa13</id>
<content type='text'>
acpi_companion_match() doesn't alter the contents of the passed
parameter, so we don't expect that returned value can be altered
either. So constify it.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
acpi_companion_match() doesn't alter the contents of the passed
parameter, so we don't expect that returned value can be altered
either. So constify it.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: scan: Move acpi_root to internal header</title>
<updated>2023-06-29T08:47:37+00:00</updated>
<author>
<name>Andy Shevchenko</name>
<email>andriy.shevchenko@linux.intel.com</email>
</author>
<published>2023-06-26T10:55:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7ba6b73db3dbe6cf365a8122e4ce36559a7714cc'/>
<id>7ba6b73db3dbe6cf365a8122e4ce36559a7714cc</id>
<content type='text'>
Compiler is not happy about handling of acpi_root variable:

  ...drivers/acpi/bus.c:37:20: warning: symbol 'acpi_root' was not declared. Should it be static?

Move it's definition to the internal header.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Compiler is not happy about handling of acpi_root variable:

  ...drivers/acpi/bus.c:37:20: warning: symbol 'acpi_root' was not declared. Should it be static?

Move it's definition to the internal header.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>driver core: make struct device_type.uevent() take a const *</title>
<updated>2023-01-27T12:45:36+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2023-01-11T11:30:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=162736b0d71a9630f7c99dda7cefd5600fa03d69'/>
<id>162736b0d71a9630f7c99dda7cefd5600fa03d69</id>
<content type='text'>
The uevent() callback in struct device_type should not be modifying the
device that is passed into it, so mark it as a const * and propagate the
function signature changes out into all relevant subsystems that use
this callback.

Cc: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: Andreas Noever &lt;andreas.noever@gmail.com&gt;
Cc: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Cc: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;
Cc: Frank Rowand &lt;frowand.list@gmail.com&gt;
Cc: Ira Weiny &lt;ira.weiny@intel.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Jilin Yuan &lt;yuanjilin@cdjrlc.com&gt;
Cc: Jiri Slaby &lt;jirislaby@kernel.org&gt;
Cc: Len Brown &lt;lenb@kernel.org&gt;
Cc: Mark Gross &lt;markgross@kernel.org&gt;
Cc: "Martin K. Petersen" &lt;martin.petersen@oracle.com&gt;
Cc: "Matthew Wilcox (Oracle)" &lt;willy@infradead.org&gt;
Cc: Maximilian Luz &lt;luzmaximilian@gmail.com&gt;
Cc: Michael Jamet &lt;michael.jamet@intel.com&gt;
Cc: Ming Lei &lt;ming.lei@redhat.com&gt;
Cc: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Cc: Rob Herring &lt;robh+dt@kernel.org&gt;
Cc: Sakari Ailus &lt;sakari.ailus@linux.intel.com&gt;
Cc: Sanyog Kale &lt;sanyog.r.kale@intel.com&gt;
Cc: Sean Young &lt;sean@mess.org&gt;
Cc: Stefan Richter &lt;stefanr@s5r6.in-berlin.de&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Won Chung &lt;wonchung@google.com&gt;
Cc: Yehezkel Bernat &lt;YehezkelShB@gmail.com&gt;
Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt; # for Thunderbolt
Acked-by: Mauro Carvalho Chehab &lt;mchehab@kernel.org&gt;
Acked-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Acked-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Acked-by: Wolfram Sang &lt;wsa@kernel.org&gt;
Acked-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Acked-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20230111113018.459199-6-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The uevent() callback in struct device_type should not be modifying the
device that is passed into it, so mark it as a const * and propagate the
function signature changes out into all relevant subsystems that use
this callback.

Cc: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: Andreas Noever &lt;andreas.noever@gmail.com&gt;
Cc: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: Bard Liao &lt;yung-chuan.liao@linux.intel.com&gt;
Cc: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;
Cc: Frank Rowand &lt;frowand.list@gmail.com&gt;
Cc: Ira Weiny &lt;ira.weiny@intel.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Jilin Yuan &lt;yuanjilin@cdjrlc.com&gt;
Cc: Jiri Slaby &lt;jirislaby@kernel.org&gt;
Cc: Len Brown &lt;lenb@kernel.org&gt;
Cc: Mark Gross &lt;markgross@kernel.org&gt;
Cc: "Martin K. Petersen" &lt;martin.petersen@oracle.com&gt;
Cc: "Matthew Wilcox (Oracle)" &lt;willy@infradead.org&gt;
Cc: Maximilian Luz &lt;luzmaximilian@gmail.com&gt;
Cc: Michael Jamet &lt;michael.jamet@intel.com&gt;
Cc: Ming Lei &lt;ming.lei@redhat.com&gt;
Cc: Pierre-Louis Bossart &lt;pierre-louis.bossart@linux.intel.com&gt;
Cc: Rob Herring &lt;robh+dt@kernel.org&gt;
Cc: Sakari Ailus &lt;sakari.ailus@linux.intel.com&gt;
Cc: Sanyog Kale &lt;sanyog.r.kale@intel.com&gt;
Cc: Sean Young &lt;sean@mess.org&gt;
Cc: Stefan Richter &lt;stefanr@s5r6.in-berlin.de&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Won Chung &lt;wonchung@google.com&gt;
Cc: Yehezkel Bernat &lt;YehezkelShB@gmail.com&gt;
Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Acked-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt; # for Thunderbolt
Acked-by: Mauro Carvalho Chehab &lt;mchehab@kernel.org&gt;
Acked-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Acked-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Acked-by: Wolfram Sang &lt;wsa@kernel.org&gt;
Acked-by: Vinod Koul &lt;vkoul@kernel.org&gt;
Acked-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20230111113018.459199-6-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: EC: Fix EC address space handler unregistration</title>
<updated>2022-12-08T16:42:12+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2022-12-08T14:23:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a5072078dbfaa9d70130805766dfa34bbb7bf2a7'/>
<id>a5072078dbfaa9d70130805766dfa34bbb7bf2a7</id>
<content type='text'>
When an ECDT table is present the EC address space handler gets registered
on the root node. So to unregister it properly the unregister call also
must be done on the root node.

Store the ACPI handle used for the acpi_install_address_space_handler()
call and use te same handle for the acpi_remove_address_space_handler()
call.

Reported-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When an ECDT table is present the EC address space handler gets registered
on the root node. So to unregister it properly the unregister call also
must be done on the root node.

Store the ACPI handle used for the acpi_install_address_space_handler()
call and use te same handle for the acpi_remove_address_space_handler()
call.

Reported-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: scan: Eliminate __acpi_device_add()</title>
<updated>2022-08-23T16:19:27+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2022-08-10T16:17:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6e1850b2f3747942d3813a2fde82f1e46aa593d1'/>
<id>6e1850b2f3747942d3813a2fde82f1e46aa593d1</id>
<content type='text'>
Instead of having acpi_device_add() defined as a wrapper around
__acpi_device_add(), export acpi_tie_acpi_dev() so it can be called
directly by acpi_add_power_resource(), fold acpi_device_add() into the
latter and rename __acpi_device_add() to acpi_device_add().

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Punit Agrawal &lt;punit.agrawal@bytedance.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Instead of having acpi_device_add() defined as a wrapper around
__acpi_device_add(), export acpi_tie_acpi_dev() so it can be called
directly by acpi_add_power_resource(), fold acpi_device_add() into the
latter and rename __acpi_device_add() to acpi_device_add().

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Punit Agrawal &lt;punit.agrawal@bytedance.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: scan: Rearrange initialization of ACPI device objects</title>
<updated>2022-08-23T16:19:27+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2022-08-10T16:16:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5c5e1237032aaa39107e2d0bb8e6cb84b3c41161'/>
<id>5c5e1237032aaa39107e2d0bb8e6cb84b3c41161</id>
<content type='text'>
The initialization of ACPI device objects is split between
acpi_init_device_object() and __acpi_device_add() that initializes
the dev field in struct acpi_device.  The "release" function pointer
is passed to __acpi_device_add() for this reason.

However, that split is artificial and all of the initialization can
be carried out by acpi_init_device_object(), so rearrange the code
to that end.  In particular, make acpi_init_device_object() take the
"release" pointer as an argument, along with the "type" which is
related to it, instead of __acpi_device_add().

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Punit Agrawal &lt;punit.agrawal@bytedance.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The initialization of ACPI device objects is split between
acpi_init_device_object() and __acpi_device_add() that initializes
the dev field in struct acpi_device.  The "release" function pointer
is passed to __acpi_device_add() for this reason.

However, that split is artificial and all of the initialization can
be carried out by acpi_init_device_object(), so rearrange the code
to that end.  In particular, make acpi_init_device_object() take the
"release" pointer as an argument, along with the "type" which is
related to it, instead of __acpi_device_add().

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Punit Agrawal &lt;punit.agrawal@bytedance.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: scan: Use ida_alloc() instead of ida_simple_get()</title>
<updated>2022-02-18T19:16:34+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2022-02-10T20:05:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ad2f3b08d1ab17e481df753aae221f085fe1cc8a'/>
<id>ad2f3b08d1ab17e481df753aae221f085fe1cc8a</id>
<content type='text'>
As recommended in include/linux/idr.h, use ida_alloc() instead of
ida_simple_get() for creating unique device object names and for
symmetry replace ida_simple_remove() with ida_free() (and fix up
the related overly long code line while at it).

Also drop the ACPI_MAX_DEVICE_INSTANCES limit that is not necessary
any more and may not be sufficient for future platforms.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As recommended in include/linux/idr.h, use ida_alloc() instead of
ida_simple_get() for creating unique device object names and for
symmetry replace ida_simple_remove() with ida_free() (and fix up
the related overly long code line while at it).

Also drop the ACPI_MAX_DEVICE_INSTANCES limit that is not necessary
any more and may not be sufficient for future platforms.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: scan: Change acpi_scan_init() return value type to void</title>
<updated>2022-01-12T14:58:49+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2022-01-11T16:50:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b6c55b162bcee62c43c18e59f38a4590be543032'/>
<id>b6c55b162bcee62c43c18e59f38a4590be543032</id>
<content type='text'>
The only caller of acpi_scan_init(), acpi_init(), doesn't check its
return value, so turn it into a void function.

This avoids complaints from the Smatch static checker that the
function should return a negative error code when it fails, which
is not really a problem in this particular case.

No intentional functional impact.

Link: https://lore.kernel.org/linux-acpi/20220106082317.GA9123@kili/
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The only caller of acpi_scan_init(), acpi_init(), doesn't check its
return value, so turn it into a void function.

This avoids complaints from the Smatch static checker that the
function should return a negative error code when it fails, which
is not really a problem in this particular case.

No intentional functional impact.

Link: https://lore.kernel.org/linux-acpi/20220106082317.GA9123@kili/
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: EC: Make the event work state machine visible</title>
<updated>2021-12-01T19:17:32+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2021-11-23T18:44:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c33676aa48249b007d55198dc8348cd117e3d8cc'/>
<id>c33676aa48249b007d55198dc8348cd117e3d8cc</id>
<content type='text'>
The EC driver uses a relatively simple state machine for the event
work handling, but it is not really straightforward to figure out.

The states are as follows:

 "Ready": The event handling work can be submitted.

  In this state, the EC_FLAGS_QUERY_PENDING flag is clear.

 "In progress": The event handling work is pending or is being
                processed.  It cannot be submitted again.

  In ths state, the EC_FLAGS_QUERY_PENDING flag is set and both the
  events_to_process count is nonzero and the EC_FLAGS_QUERY_GUARDING
  flag is clear.

 "Complete": The event handling work has been completed, but it still
             cannot be submitted again.

  In ths state, the EC_FLAGS_QUERY_PENDING flag is set and the
  events_to_process count is zero or the EC_FLAGS_QUERY_GUARDING
  flag is set.

The state changes from "Ready" to "In progress" when new event is
detected by advance_transaction() and acpi_ec_submit_event() is
called by it.

Next, the state can change from "In progress" directly to "Ready" in
the following situations:

 * ec_event_clearing is ACPI_EC_EVT_TIMING_STATUS and the state of
   an ACPI_EC_COMMAND_QUERY transaction becomes ACPI_EC_COMMAND_POLL.

 * ec_event_clearing is ACPI_EC_EVT_TIMING_QUERY and the state of
   an ACPI_EC_COMMAND_QUERY transaction becomes
   ACPI_EC_COMMAND_COMPLETE.

 * ec_event_clearing is either ACPI_EC_EVT_TIMING_STATUS or
   ACPI_EC_EVT_TIMING_QUERY and there are no more events to
   process (ie. ec-&gt;events_to_process becomes 0).

If ec_event_clearing is ACPI_EC_EVT_TIMING_EVENT, however, the
state must change from "In progress" to "Complete" before it
can change to "Ready".  The changes from "In progress" to
"Complete" in that case occur in the following situations:

 * The state of an ACPI_EC_COMMAND_QUERY transaction becomes
   ACPI_EC_COMMAND_COMPLETE.

 * There are no more events to process (ie. ec-&gt;events_to_process
   becomes 0).

Finally, the state changes from "Complete" to "Ready" when
advance_transaction() is invoked when the state is "Complete" and
the state of the current transaction is not ACPI_EC_COMMAND_POLL.

To make this state machine visible in the code, add a new
event_state field to struct acpi_ec and modify the code to use
it istead the EC_FLAGS_QUERY_PENDING and EC_FLAGS_QUERY_GUARDING
flags.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The EC driver uses a relatively simple state machine for the event
work handling, but it is not really straightforward to figure out.

The states are as follows:

 "Ready": The event handling work can be submitted.

  In this state, the EC_FLAGS_QUERY_PENDING flag is clear.

 "In progress": The event handling work is pending or is being
                processed.  It cannot be submitted again.

  In ths state, the EC_FLAGS_QUERY_PENDING flag is set and both the
  events_to_process count is nonzero and the EC_FLAGS_QUERY_GUARDING
  flag is clear.

 "Complete": The event handling work has been completed, but it still
             cannot be submitted again.

  In ths state, the EC_FLAGS_QUERY_PENDING flag is set and the
  events_to_process count is zero or the EC_FLAGS_QUERY_GUARDING
  flag is set.

The state changes from "Ready" to "In progress" when new event is
detected by advance_transaction() and acpi_ec_submit_event() is
called by it.

Next, the state can change from "In progress" directly to "Ready" in
the following situations:

 * ec_event_clearing is ACPI_EC_EVT_TIMING_STATUS and the state of
   an ACPI_EC_COMMAND_QUERY transaction becomes ACPI_EC_COMMAND_POLL.

 * ec_event_clearing is ACPI_EC_EVT_TIMING_QUERY and the state of
   an ACPI_EC_COMMAND_QUERY transaction becomes
   ACPI_EC_COMMAND_COMPLETE.

 * ec_event_clearing is either ACPI_EC_EVT_TIMING_STATUS or
   ACPI_EC_EVT_TIMING_QUERY and there are no more events to
   process (ie. ec-&gt;events_to_process becomes 0).

If ec_event_clearing is ACPI_EC_EVT_TIMING_EVENT, however, the
state must change from "In progress" to "Complete" before it
can change to "Ready".  The changes from "In progress" to
"Complete" in that case occur in the following situations:

 * The state of an ACPI_EC_COMMAND_QUERY transaction becomes
   ACPI_EC_COMMAND_COMPLETE.

 * There are no more events to process (ie. ec-&gt;events_to_process
   becomes 0).

Finally, the state changes from "Complete" to "Ready" when
advance_transaction() is invoked when the state is "Complete" and
the state of the current transaction is not ACPI_EC_COMMAND_POLL.

To make this state machine visible in the code, add a new
event_state field to struct acpi_ec and modify the code to use
it istead the EC_FLAGS_QUERY_PENDING and EC_FLAGS_QUERY_GUARDING
flags.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
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