<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/acpi/resource.c, branch linux-3.16.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>ACPI / PNP: Reserve ACPI resources at the fs_initcall_sync stage</title>
<updated>2015-07-15T09:01:34+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2015-07-04T01:09:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=669b7b31abcdc376ae9a4d03df7d7fc0fbccd1e7'/>
<id>669b7b31abcdc376ae9a4d03df7d7fc0fbccd1e7</id>
<content type='text'>
commit 0294112ee3135fbd15eaa70015af8283642dd970 upstream.

This effectively reverts the following three commits:

 7bc10388ccdd ACPI / resources: free memory on error in add_region_before()
 0f1b414d1907 ACPI / PNP: Avoid conflicting resource reservations
 b9a5e5e18fbf ACPI / init: Fix the ordering of acpi_reserve_resources()

(commit b9a5e5e18fbf introduced regressions some of which, but not
all, were addressed by commit 0f1b414d1907 and commit 7bc10388ccdd
was a fixup on top of the latter) and causes ACPI fixed hardware
resources to be reserved at the fs_initcall_sync stage of system
initialization.

The story is as follows.  First, a boot regression was reported due
to an apparent resource reservation ordering change after a commit
that shouldn't lead to such changes.  Investigation led to the
conclusion that the problem happened because acpi_reserve_resources()
was executed at the device_initcall() stage of system initialization
which wasn't strictly ordered with respect to driver initialization
(and with respect to the initialization of the pcieport driver in
particular), so a random change causing the device initcalls to be
run in a different order might break things.

The response to that was to attempt to run acpi_reserve_resources()
as soon as we knew that ACPI would be in use (commit b9a5e5e18fbf).
However, that turned out to be too early, because it caused resource
reservations made by the PNP system driver to fail on at least one
system and that failure was addressed by commit 0f1b414d1907.

That fix still turned out to be insufficient, though, because
calling acpi_reserve_resources() before the fs_initcall stage of
system initialization caused a boot regression to happen on the
eCAFE EC-800-H20G/S netbook.  That meant that we only could call
acpi_reserve_resources() at the fs_initcall initialization stage
or later, but then we might just as well call it after the PNP
initalization in which case commit 0f1b414d1907 wouldn't be
necessary any more.

For this reason, the changes made by commit 0f1b414d1907 are reverted
(along with a memory leak fixup on top of that commit), the changes
made by commit b9a5e5e18fbf that went too far are reverted too and
acpi_reserve_resources() is changed into fs_initcall_sync, which
will cause it to be executed after the PNP subsystem initialization
(which is an fs_initcall) and before device initcalls (including
the pcieport driver initialization) which should avoid the initial
issue.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=100581
Link: http://marc.info/?t=143092384600002&amp;r=1&amp;w=2
Link: https://bugzilla.kernel.org/show_bug.cgi?id=99831
Link: http://marc.info/?t=143389402600001&amp;r=1&amp;w=2
Fixes: b9a5e5e18fbf "ACPI / init: Fix the ordering of acpi_reserve_resources()"
Reported-by: Roland Dreier &lt;roland@purestorage.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Luis Henriques &lt;luis.henriques@canonical.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 0294112ee3135fbd15eaa70015af8283642dd970 upstream.

This effectively reverts the following three commits:

 7bc10388ccdd ACPI / resources: free memory on error in add_region_before()
 0f1b414d1907 ACPI / PNP: Avoid conflicting resource reservations
 b9a5e5e18fbf ACPI / init: Fix the ordering of acpi_reserve_resources()

(commit b9a5e5e18fbf introduced regressions some of which, but not
all, were addressed by commit 0f1b414d1907 and commit 7bc10388ccdd
was a fixup on top of the latter) and causes ACPI fixed hardware
resources to be reserved at the fs_initcall_sync stage of system
initialization.

The story is as follows.  First, a boot regression was reported due
to an apparent resource reservation ordering change after a commit
that shouldn't lead to such changes.  Investigation led to the
conclusion that the problem happened because acpi_reserve_resources()
was executed at the device_initcall() stage of system initialization
which wasn't strictly ordered with respect to driver initialization
(and with respect to the initialization of the pcieport driver in
particular), so a random change causing the device initcalls to be
run in a different order might break things.

The response to that was to attempt to run acpi_reserve_resources()
as soon as we knew that ACPI would be in use (commit b9a5e5e18fbf).
However, that turned out to be too early, because it caused resource
reservations made by the PNP system driver to fail on at least one
system and that failure was addressed by commit 0f1b414d1907.

That fix still turned out to be insufficient, though, because
calling acpi_reserve_resources() before the fs_initcall stage of
system initialization caused a boot regression to happen on the
eCAFE EC-800-H20G/S netbook.  That meant that we only could call
acpi_reserve_resources() at the fs_initcall initialization stage
or later, but then we might just as well call it after the PNP
initalization in which case commit 0f1b414d1907 wouldn't be
necessary any more.

For this reason, the changes made by commit 0f1b414d1907 are reverted
(along with a memory leak fixup on top of that commit), the changes
made by commit b9a5e5e18fbf that went too far are reverted too and
acpi_reserve_resources() is changed into fs_initcall_sync, which
will cause it to be executed after the PNP subsystem initialization
(which is an fs_initcall) and before device initcalls (including
the pcieport driver initialization) which should avoid the initial
issue.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=100581
Link: http://marc.info/?t=143092384600002&amp;r=1&amp;w=2
Link: https://bugzilla.kernel.org/show_bug.cgi?id=99831
Link: http://marc.info/?t=143389402600001&amp;r=1&amp;w=2
Fixes: b9a5e5e18fbf "ACPI / init: Fix the ordering of acpi_reserve_resources()"
Reported-by: Roland Dreier &lt;roland@purestorage.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Luis Henriques &lt;luis.henriques@canonical.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / resources: free memory on error in add_region_before()</title>
<updated>2015-07-15T09:00:51+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@oracle.com</email>
</author>
<published>2015-06-24T14:30:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8d6015e0ede2d98d1f9b18877cae15fdddd7abb8'/>
<id>8d6015e0ede2d98d1f9b18877cae15fdddd7abb8</id>
<content type='text'>
commit 7bc10388ccdd79b3d20463151a1f8e7a590a775b upstream.

There is a small memory leak on error.

Fixes: 0f1b414d1907 (ACPI / PNP: Avoid conflicting resource reservations)
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Luis Henriques &lt;luis.henriques@canonical.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 7bc10388ccdd79b3d20463151a1f8e7a590a775b upstream.

There is a small memory leak on error.

Fixes: 0f1b414d1907 (ACPI / PNP: Avoid conflicting resource reservations)
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Luis Henriques &lt;luis.henriques@canonical.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / PNP: Avoid conflicting resource reservations</title>
<updated>2015-07-15T09:00:43+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2015-06-18T16:32:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a6091c181e0ae5826355debcb3da34135b646d5b'/>
<id>a6091c181e0ae5826355debcb3da34135b646d5b</id>
<content type='text'>
commit 0f1b414d190724617eb1cdd615592fa8cd9d0b50 upstream.

Commit b9a5e5e18fbf "ACPI / init: Fix the ordering of
acpi_reserve_resources()" overlooked the fact that the memory
and/or I/O regions reserved by acpi_reserve_resources() may
conflict with those reserved by the PNP "system" driver.

If that conflict actually takes place, it causes the reservations
made by the "system" driver to fail while before commit b9a5e5e18fbf
all reservations made by it and by acpi_reserve_resources() would be
successful.  In turn, that allows the resources that haven't been
reserved by the "system" driver to be used by others (e.g. PCI) which
sometimes leads to functional problems (up to and including boot
failures).

To fix that issue, introduce a common resource reservation routine,
acpi_reserve_region(), to be used by both acpi_reserve_resources()
and the "system" driver, that will track all resources reserved by
it and avoid making conflicting requests.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=99831
Link: http://marc.info/?t=143389402600001&amp;r=1&amp;w=2
Fixes: b9a5e5e18fbf "ACPI / init: Fix the ordering of acpi_reserve_resources()"
Reported-by: Roland Dreier &lt;roland@purestorage.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques &lt;luis.henriques@canonical.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 0f1b414d190724617eb1cdd615592fa8cd9d0b50 upstream.

Commit b9a5e5e18fbf "ACPI / init: Fix the ordering of
acpi_reserve_resources()" overlooked the fact that the memory
and/or I/O regions reserved by acpi_reserve_resources() may
conflict with those reserved by the PNP "system" driver.

If that conflict actually takes place, it causes the reservations
made by the "system" driver to fail while before commit b9a5e5e18fbf
all reservations made by it and by acpi_reserve_resources() would be
successful.  In turn, that allows the resources that haven't been
reserved by the "system" driver to be used by others (e.g. PCI) which
sometimes leads to functional problems (up to and including boot
failures).

To fix that issue, introduce a common resource reservation routine,
acpi_reserve_region(), to be used by both acpi_reserve_resources()
and the "system" driver, that will track all resources reserved by
it and avoid making conflicting requests.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=99831
Link: http://marc.info/?t=143389402600001&amp;r=1&amp;w=2
Fixes: b9a5e5e18fbf "ACPI / init: Fix the ordering of acpi_reserve_resources()"
Reported-by: Roland Dreier &lt;roland@purestorage.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques &lt;luis.henriques@canonical.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / resources: only reject zero length resources based at address zero</title>
<updated>2014-07-07T20:11:09+00:00</updated>
<author>
<name>Andy Whitcroft</name>
<email>apw@canonical.com</email>
</author>
<published>2014-06-19T10:19:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=867f9d463b82462793ea4610e748be0b04b37fc7'/>
<id>867f9d463b82462793ea4610e748be0b04b37fc7</id>
<content type='text'>
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 &lt;rui.zhang@intel.com&gt;
  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 &lt;apw@canonical.com&gt;
Acked-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Cc: 3.14+ &lt;stable@vger.kernel.org&gt; # 3.14+
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 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 &lt;rui.zhang@intel.com&gt;
  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 &lt;apw@canonical.com&gt;
Acked-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Cc: 3.14+ &lt;stable@vger.kernel.org&gt; # 3.14+
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / resources: ignore invalid ACPI device resources</title>
<updated>2014-03-01T21:46:05+00:00</updated>
<author>
<name>Zhang Rui</name>
<email>rui.zhang@intel.com</email>
</author>
<published>2014-02-27T03:37:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b355cee88e3b1a193f0e9a81db810f6f83ad728b'/>
<id>b355cee88e3b1a193f0e9a81db810f6f83ad728b</id>
<content type='text'>
ACPI table may export resource entry with 0 length.
But the current code interprets this kind of resource in a wrong way.
It will create a resource structure with
res-&gt;end = acpi_resource-&gt;start + acpi_resource-&gt;len - 1;

This patch fixes a problem on my machine that a platform device fails
to be created because one of its ACPI IO resource entry (start = 0,
end = 0, length = 0) is translated into a generic resource with
start = 0, end = 0xffffffff.

Signed-off-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Cc: All applicable &lt;stable@vger.kernel.org&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 table may export resource entry with 0 length.
But the current code interprets this kind of resource in a wrong way.
It will create a resource structure with
res-&gt;end = acpi_resource-&gt;start + acpi_resource-&gt;len - 1;

This patch fixes a problem on my machine that a platform device fails
to be created because one of its ACPI IO resource entry (start = 0,
end = 0, length = 0) is translated into a generic resource with
start = 0, end = 0xffffffff.

Signed-off-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: introduce helper function acpi_has_method()</title>
<updated>2013-07-14T23:33:10+00:00</updated>
<author>
<name>Jiang Liu</name>
<email>jiang.liu@huawei.com</email>
</author>
<published>2013-06-28T16:24:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=952c63e9512b63220886105cfc791507046fa39a'/>
<id>952c63e9512b63220886105cfc791507046fa39a</id>
<content type='text'>
Introduce helper function acpi_has_method() and use it in a number
of places to simplify code.

[rjw: Changelog]
Signed-off-by: Jiang Liu &lt;jiang.liu@huawei.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>
Introduce helper function acpi_has_method() and use it in a number
of places to simplify code.

[rjw: Changelog]
Signed-off-by: Jiang Liu &lt;jiang.liu@huawei.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / resources: call acpi_get_override_irq() only for legacy IRQ resources</title>
<updated>2013-06-19T21:55:59+00:00</updated>
<author>
<name>Mika Westerberg</name>
<email>mika.westerberg@linux.intel.com</email>
</author>
<published>2013-05-20T15:41:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=204ebc0aa30a7115f300cac39fbb7eeb66524881'/>
<id>204ebc0aa30a7115f300cac39fbb7eeb66524881</id>
<content type='text'>
acpi_get_override_irq() was added because there was a problem with
buggy BIOSes passing wrong IRQ() resource for the RTC IRQ.  The
commit that added the workaround was 61fd47e0c8476 (ACPI: fix two
IRQ8 issues in IOAPIC mode).

With ACPI 5 enumerated devices there are typically one or more
extended IRQ resources per device (and these IRQs can be shared).
However, the acpi_get_override_irq() workaround forces all IRQs in
range 0 - 15 (the legacy ISA IRQs) to be edge triggered, active high
as can be seen from the dmesg below:

	ACPI: IRQ 6 override to edge, high
	ACPI: IRQ 7 override to edge, high
	ACPI: IRQ 7 override to edge, high
	ACPI: IRQ 13 override to edge, high

Also /proc/interrupts for the I2C controllers (INT33C2 and INT33C3) shows
the same thing:

	7:          4          0          0          0   IO-APIC-edge INT33C2:00, INT33C3:00

The _CSR method for INT33C2 (and INT33C3) device returns following
resource:

	Interrupt (ResourceConsumer, Level, ActiveLow, Shared,,, )
	{
		0x00000007,
	}

which states that this is supposed to be level triggered, active low,
shared IRQ instead.

Fix this by making sure that acpi_get_override_irq() gets only called
when we are dealing with legacy IRQ() or IRQNoFlags() descriptors.

While we are there, correct pr_warning() to print the right triggering
value.

This change turns out to be necessary to make DMA work correctly on
systems based on the Intel Lynxpoint PCH (Platform Controller Hub).

[rjw: Changelog]
Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Cc: 3.9+ &lt;stable@vger.kernel.org&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_get_override_irq() was added because there was a problem with
buggy BIOSes passing wrong IRQ() resource for the RTC IRQ.  The
commit that added the workaround was 61fd47e0c8476 (ACPI: fix two
IRQ8 issues in IOAPIC mode).

With ACPI 5 enumerated devices there are typically one or more
extended IRQ resources per device (and these IRQs can be shared).
However, the acpi_get_override_irq() workaround forces all IRQs in
range 0 - 15 (the legacy ISA IRQs) to be edge triggered, active high
as can be seen from the dmesg below:

	ACPI: IRQ 6 override to edge, high
	ACPI: IRQ 7 override to edge, high
	ACPI: IRQ 7 override to edge, high
	ACPI: IRQ 13 override to edge, high

Also /proc/interrupts for the I2C controllers (INT33C2 and INT33C3) shows
the same thing:

	7:          4          0          0          0   IO-APIC-edge INT33C2:00, INT33C3:00

The _CSR method for INT33C2 (and INT33C3) device returns following
resource:

	Interrupt (ResourceConsumer, Level, ActiveLow, Shared,,, )
	{
		0x00000007,
	}

which states that this is supposed to be level triggered, active low,
shared IRQ instead.

Fix this by making sure that acpi_get_override_irq() gets only called
when we are dealing with legacy IRQ() or IRQNoFlags() descriptors.

While we are there, correct pr_warning() to print the right triggering
value.

This change turns out to be necessary to make DMA work correctly on
systems based on the Intel Lynxpoint PCH (Platform Controller Hub).

[rjw: Changelog]
Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Cc: 3.9+ &lt;stable@vger.kernel.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: remove unnecessary INIT_LIST_HEAD</title>
<updated>2012-11-27T12:49:36+00:00</updated>
<author>
<name>Andy Shevchenko</name>
<email>andriy.shevchenko@linux.intel.com</email>
</author>
<published>2012-11-27T12:49:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=752cad760b19e85926341880dc317a99f400eacc'/>
<id>752cad760b19e85926341880dc317a99f400eacc</id>
<content type='text'>
There is no need to initialize the node before appending it to the list.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@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>
There is no need to initialize the node before appending it to the list.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / resources: Use AE_CTRL_TERMINATE to terminate resources walks</title>
<updated>2012-11-16T20:55:48+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2012-11-16T20:55:48+00:00</published>
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<content type='text'>
Currently acpi_dev_process_resource() returns AE_ABORT_METHOD
to terminate the acpi_walk_resources() it is called from if
the .preproc() routine provided by the caller of
acpi_dev_get_resources() initiating the resources walk returns
an error code.  It is better to use AE_CTRL_TERMINATE for this
purpose, however, so do that.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
</content>
<content type='xhtml'>
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<pre>
Currently acpi_dev_process_resource() returns AE_ABORT_METHOD
to terminate the acpi_walk_resources() it is called from if
the .preproc() routine provided by the caller of
acpi_dev_get_resources() initiating the resources walk returns
an error code.  It is better to use AE_CTRL_TERMINATE for this
purpose, however, so do that.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: Centralized processing of ACPI device resources</title>
<updated>2012-11-14T23:30:21+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2012-11-14T23:30:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8e345c991c8c7a3c081199ef77deada79e37618a'/>
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Currently, whoever wants to use ACPI device resources has to call
acpi_walk_resources() to browse the buffer returned by the _CRS
method for the given device and create filters passed to that
routine to apply to the individual resource items.  This generally
is cumbersome, time-consuming and inefficient.  Moreover, it may
be problematic if resource conflicts need to be resolved, because
the different users of _CRS will need to do that in a consistent
way.  However, if there are resource conflicts, the ACPI core
should be able to resolve them centrally instead of relying on
various users of acpi_walk_resources() to handle them correctly
together.

For this reason, introduce a new function, acpi_dev_get_resources(),
that can be used by subsystems to obtain a list of struct resource
objects corresponding to the ACPI device resources returned by
_CRS and, if necessary, to apply additional preprocessing routine
to the ACPI resources before converting them to the struct resource
format.

Make the ACPI code that creates platform device objects use
acpi_dev_get_resources() for resource processing instead of executing
acpi_walk_resources() twice by itself, which causes it to be much
more straightforward and easier to follow.

In the future, acpi_dev_get_resources() can be extended to meet
the needs of the ACPI PNP subsystem and other users of _CRS in
the kernel.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Tested-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, whoever wants to use ACPI device resources has to call
acpi_walk_resources() to browse the buffer returned by the _CRS
method for the given device and create filters passed to that
routine to apply to the individual resource items.  This generally
is cumbersome, time-consuming and inefficient.  Moreover, it may
be problematic if resource conflicts need to be resolved, because
the different users of _CRS will need to do that in a consistent
way.  However, if there are resource conflicts, the ACPI core
should be able to resolve them centrally instead of relying on
various users of acpi_walk_resources() to handle them correctly
together.

For this reason, introduce a new function, acpi_dev_get_resources(),
that can be used by subsystems to obtain a list of struct resource
objects corresponding to the ACPI device resources returned by
_CRS and, if necessary, to apply additional preprocessing routine
to the ACPI resources before converting them to the struct resource
format.

Make the ACPI code that creates platform device objects use
acpi_dev_get_resources() for resource processing instead of executing
acpi_walk_resources() twice by itself, which causes it to be much
more straightforward and easier to follow.

In the future, acpi_dev_get_resources() can be extended to meet
the needs of the ACPI PNP subsystem and other users of _CRS in
the kernel.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Tested-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
