<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/acpi, branch v4.2-rc4</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge branches 'pm-cpuidle', 'pm-cpufreq' and 'acpi-resources'</title>
<updated>2015-07-16T21:47:19+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2015-07-16T21:47:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=17ffc8b083ac299ff798419d1887b7cdcd4ae4d2'/>
<id>17ffc8b083ac299ff798419d1887b7cdcd4ae4d2</id>
<content type='text'>
* pm-cpuidle:
  suspend-to-idle: Prevent RCU from complaining about tick_freeze()

* pm-cpufreq:
  cpufreq: Allow freq_table to be obtained for offline CPUs
  cpufreq: Initialize the governor again while restoring policy

* acpi-resources:
  ACPI / PCI: Fix regressions caused by resource_size_t overflow with 32-bit kernel
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* pm-cpuidle:
  suspend-to-idle: Prevent RCU from complaining about tick_freeze()

* pm-cpufreq:
  cpufreq: Allow freq_table to be obtained for offline CPUs
  cpufreq: Initialize the governor again while restoring policy

* acpi-resources:
  ACPI / PCI: Fix regressions caused by resource_size_t overflow with 32-bit kernel
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm</title>
<updated>2015-07-12T03:44:31+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-07-12T03:44:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=59c3cb553f5fc4ed6868eeaae6ffd8e1daf6d93e'/>
<id>59c3cb553f5fc4ed6868eeaae6ffd8e1daf6d93e</id>
<content type='text'>
Pull libnvdimm fixes from Dan Williams:
 "1) Fixes for a handful of smatch reports (Thanks Dan C.!) and minor
     bug fixes (patches 1-6)

  2) Correctness fixes to the BLK-mode nvdimm driver (patches 7-10).

     Granted these are slightly large for a -rc update.  They have been
     out for review in one form or another since the end of May and were
     deferred from the merge window while we settled on the "PMEM API"
     for the PMEM-mode nvdimm driver (ie memremap_pmem, memcpy_to_pmem,
     and wmb_pmem).

     Now that those apis are merged we implement them in the BLK driver
     to guarantee that mmio aperture moves stay ordered with respect to
     incoming read/write requests, and that writes are flushed through
     those mmio-windows and platform-buffers to be persistent on media.

  These pass the sub-system unit tests with the updates to
  tools/testing/nvdimm, and have received a successful build-report from
  the kbuild robot (468 configs).

  With acks from Rafael for the touches to drivers/acpi/"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm:
  nfit: add support for NVDIMM "latch" flag
  nfit: update block I/O path to use PMEM API
  tools/testing/nvdimm: add mock acpi_nfit_flush_address entries to nfit_test
  tools/testing/nvdimm: fix return code for unimplemented commands
  tools/testing/nvdimm: mock ioremap_wt
  pmem: add maintainer for include/linux/pmem.h
  nfit: fix smatch "use after null check" report
  nvdimm: Fix return value of nvdimm_bus_init() if class_create() fails
  libnvdimm: smatch cleanups in __nd_ioctl
  sparse: fix misplaced __pmem definition
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull libnvdimm fixes from Dan Williams:
 "1) Fixes for a handful of smatch reports (Thanks Dan C.!) and minor
     bug fixes (patches 1-6)

  2) Correctness fixes to the BLK-mode nvdimm driver (patches 7-10).

     Granted these are slightly large for a -rc update.  They have been
     out for review in one form or another since the end of May and were
     deferred from the merge window while we settled on the "PMEM API"
     for the PMEM-mode nvdimm driver (ie memremap_pmem, memcpy_to_pmem,
     and wmb_pmem).

     Now that those apis are merged we implement them in the BLK driver
     to guarantee that mmio aperture moves stay ordered with respect to
     incoming read/write requests, and that writes are flushed through
     those mmio-windows and platform-buffers to be persistent on media.

  These pass the sub-system unit tests with the updates to
  tools/testing/nvdimm, and have received a successful build-report from
  the kbuild robot (468 configs).

  With acks from Rafael for the touches to drivers/acpi/"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm:
  nfit: add support for NVDIMM "latch" flag
  nfit: update block I/O path to use PMEM API
  tools/testing/nvdimm: add mock acpi_nfit_flush_address entries to nfit_test
  tools/testing/nvdimm: fix return code for unimplemented commands
  tools/testing/nvdimm: mock ioremap_wt
  pmem: add maintainer for include/linux/pmem.h
  nfit: fix smatch "use after null check" report
  nvdimm: Fix return value of nvdimm_bus_init() if class_create() fails
  libnvdimm: smatch cleanups in __nd_ioctl
  sparse: fix misplaced __pmem definition
</pre>
</div>
</content>
</entry>
<entry>
<title>nfit: add support for NVDIMM "latch" flag</title>
<updated>2015-07-10T18:43:50+00:00</updated>
<author>
<name>Ross Zwisler</name>
<email>ross.zwisler@linux.intel.com</email>
</author>
<published>2015-07-10T17:06:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f0f2c072cf530d5b8890be5051cc8b36b0c54cce'/>
<id>f0f2c072cf530d5b8890be5051cc8b36b0c54cce</id>
<content type='text'>
Add support in the NFIT BLK I/O path for the "latch" flag
defined in the "Get Block NVDIMM Flags" _DSM function:

http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf

This flag requires the driver to read back the command register after it
is written in the block I/O path.  This ensures that the hardware has
fully processed the new command and moved the aperture appropriately.

Signed-off-by: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add support in the NFIT BLK I/O path for the "latch" flag
defined in the "Get Block NVDIMM Flags" _DSM function:

http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf

This flag requires the driver to read back the command register after it
is written in the block I/O path.  This ensures that the hardware has
fully processed the new command and moved the aperture appropriately.

Signed-off-by: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nfit: update block I/O path to use PMEM API</title>
<updated>2015-07-10T18:35:45+00:00</updated>
<author>
<name>Ross Zwisler</name>
<email>ross.zwisler@linux.intel.com</email>
</author>
<published>2015-07-10T17:06:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c2ad29540cb913bd9e526fae77c35c7fb45f24a3'/>
<id>c2ad29540cb913bd9e526fae77c35c7fb45f24a3</id>
<content type='text'>
Update the nfit block I/O path to use the new PMEM API and to adhere to
the read/write flows outlined in the "NVDIMM Block Window Driver
Writer's Guide":

http://pmem.io/documents/NVDIMM_Driver_Writers_Guide.pdf

This includes adding support for targeted NVDIMM flushes called "flush
hints" in the ACPI 6.0 specification:

http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf

For performance and media durability the mapping for a BLK aperture is
moved to a write-combining mapping which is consistent with
memcpy_to_pmem() and wmb_blk().

Signed-off-by: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Update the nfit block I/O path to use the new PMEM API and to adhere to
the read/write flows outlined in the "NVDIMM Block Window Driver
Writer's Guide":

http://pmem.io/documents/NVDIMM_Driver_Writers_Guide.pdf

This includes adding support for targeted NVDIMM flushes called "flush
hints" in the ACPI 6.0 specification:

http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf

For performance and media durability the mapping for a BLK aperture is
moved to a write-combining mapping which is consistent with
memcpy_to_pmem() and wmb_blk().

Signed-off-by: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / PCI: Fix regressions caused by resource_size_t overflow with 32-bit kernel</title>
<updated>2015-07-10T00:46:52+00:00</updated>
<author>
<name>Jiang Liu</name>
<email>jiang.liu@linux.intel.com</email>
</author>
<published>2015-07-08T07:26:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1fb01ca93a1348a1469b8777326cd7632483de77'/>
<id>1fb01ca93a1348a1469b8777326cd7632483de77</id>
<content type='text'>
Zoltan Boszormenyi reported this regression:
  "There's a Realtek RTL8111/8168/8411 (PCI ID 10ec:8168, Subsystem ID
   1565:230e) network chip on the mainboard. After the r8169 driver loaded
   the IRQs in the machine went berserk. Keyboard keypressed arrived with
   considerable latency and duplicated, so no real work was possible.
   The machine responded to the power button but didn't actually power
   down. It just stuck at the powering down message. I had to press the
   power button for 4 seconds to power it down.

   The computer is a POS machine with a big battery inside. Because of this,
   either ACPI or the Realtek chip kept the bad state and after rebooting,
   the network chip didn't even show up in lspci. Not even the PXE ROM
   announced itself during boot. I had to disconnect the battery to beat
   some sense back to the computer.

   The regression happens with 4.0.5, 4.1.0-rc8 and 4.1.0-final. 3.18.16 was
   good."

The regression is caused by commit 593669c2ac0f (x86/PCI/ACPI: Use common
ACPI resource interfaces to simplify implementation). Since commit
593669c2ac0f, x86 PCI ACPI host bridge driver validates ACPI resources by
first converting an ACPI resource to a 'struct resource' structure and
then applying checks against the converted resource structure. The 'start'
and 'end' fields in 'struct resource' are defined to be type of
resource_size_t, which may be 32 bits or 64 bits depending on
CONFIG_PHYS_ADDR_T_64BIT.

This may cause incorrect resource validation results with 32-bit kernels
because 64-bit ACPI resource descriptors may get truncated when converting
to 32-bit 'start' and 'end' fields in 'struct resource'. It eventually
affects PCI resource allocation subsystem and makes some PCI devices and
the system behave abnormally due to incorrect resource assignment.

So enhance the ACPI resource parsing interfaces to ignore ACPI resource
descriptors with address/offset above 4G when running in 32-bit mode.

With the fix applied, the behavior of the machine was restored to how
3.18.16 worked, i.e. the memory range that is over 4GB is ignored again,
and lspci -vvxxx shows that everything is at the same memory window as
they were with 3.18.16.

Reported-and-tested-by: Boszormenyi Zoltan &lt;zboszor@pr.hu&gt;
Fixes: 593669c2ac0f (x86/PCI/ACPI: Use common ACPI resource interfaces to simplify implementation)
Signed-off-by: Jiang Liu &lt;jiang.liu@linux.intel.com&gt;
Cc: 4.0+ &lt;stable@vger.kernel.org&gt; # 4.0+
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>
Zoltan Boszormenyi reported this regression:
  "There's a Realtek RTL8111/8168/8411 (PCI ID 10ec:8168, Subsystem ID
   1565:230e) network chip on the mainboard. After the r8169 driver loaded
   the IRQs in the machine went berserk. Keyboard keypressed arrived with
   considerable latency and duplicated, so no real work was possible.
   The machine responded to the power button but didn't actually power
   down. It just stuck at the powering down message. I had to press the
   power button for 4 seconds to power it down.

   The computer is a POS machine with a big battery inside. Because of this,
   either ACPI or the Realtek chip kept the bad state and after rebooting,
   the network chip didn't even show up in lspci. Not even the PXE ROM
   announced itself during boot. I had to disconnect the battery to beat
   some sense back to the computer.

   The regression happens with 4.0.5, 4.1.0-rc8 and 4.1.0-final. 3.18.16 was
   good."

The regression is caused by commit 593669c2ac0f (x86/PCI/ACPI: Use common
ACPI resource interfaces to simplify implementation). Since commit
593669c2ac0f, x86 PCI ACPI host bridge driver validates ACPI resources by
first converting an ACPI resource to a 'struct resource' structure and
then applying checks against the converted resource structure. The 'start'
and 'end' fields in 'struct resource' are defined to be type of
resource_size_t, which may be 32 bits or 64 bits depending on
CONFIG_PHYS_ADDR_T_64BIT.

This may cause incorrect resource validation results with 32-bit kernels
because 64-bit ACPI resource descriptors may get truncated when converting
to 32-bit 'start' and 'end' fields in 'struct resource'. It eventually
affects PCI resource allocation subsystem and makes some PCI devices and
the system behave abnormally due to incorrect resource assignment.

So enhance the ACPI resource parsing interfaces to ignore ACPI resource
descriptors with address/offset above 4G when running in 32-bit mode.

With the fix applied, the behavior of the machine was restored to how
3.18.16 worked, i.e. the memory range that is over 4GB is ignored again,
and lspci -vvxxx shows that everything is at the same memory window as
they were with 3.18.16.

Reported-and-tested-by: Boszormenyi Zoltan &lt;zboszor@pr.hu&gt;
Fixes: 593669c2ac0f (x86/PCI/ACPI: Use common ACPI resource interfaces to simplify implementation)
Signed-off-by: Jiang Liu &lt;jiang.liu@linux.intel.com&gt;
Cc: 4.0+ &lt;stable@vger.kernel.org&gt; # 4.0+
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'acpi-scan'</title>
<updated>2015-07-07T20:48:25+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2015-07-07T20:48:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8076ca480f40c51ab87d8301c830a817b900b4d1'/>
<id>8076ca480f40c51ab87d8301c830a817b900b4d1</id>
<content type='text'>
* acpi-scan:
  ata: ahci_platform: Add ACPI _CLS matching
  ACPI / scan: Add support for ACPI _CLS device matching
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* acpi-scan:
  ata: ahci_platform: Add ACPI _CLS matching
  ACPI / scan: Add support for ACPI _CLS device matching
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'acpi-pnp', 'acpi-soc', 'pm-domains' and 'pm-sleep'</title>
<updated>2015-07-07T20:48:14+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2015-07-07T20:48:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d0aee67fa19260d772b07f144cf6c93e63431f67'/>
<id>d0aee67fa19260d772b07f144cf6c93e63431f67</id>
<content type='text'>
* acpi-pnp:
  ACPI / PNP: Reserve ACPI resources at the fs_initcall_sync stage

* acpi-soc:
  ACPI / LPSS: Fix up acpi_lpss_create_device()

* pm-domains:
  PM / Domains: Avoid infinite loops in attach/detach code

* pm-sleep:
  PM / hibernate: clarify resume documentation
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* acpi-pnp:
  ACPI / PNP: Reserve ACPI resources at the fs_initcall_sync stage

* acpi-soc:
  ACPI / LPSS: Fix up acpi_lpss_create_device()

* pm-domains:
  PM / Domains: Avoid infinite loops in attach/detach code

* pm-sleep:
  PM / hibernate: clarify resume documentation
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / scan: Add support for ACPI _CLS device matching</title>
<updated>2015-07-06T23:55:20+00:00</updated>
<author>
<name>Suthikulpanit, Suravee</name>
<email>Suravee.Suthikulpanit@amd.com</email>
</author>
<published>2015-07-06T23:55:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=26095a01d359827eeccec5459c28ddd976183179'/>
<id>26095a01d359827eeccec5459c28ddd976183179</id>
<content type='text'>
Device drivers typically use ACPI _HIDs/_CIDs listed in struct device_driver
acpi_match_table to match devices. However, for generic drivers, we do not
want to list _HID for all supported devices. Also, certain classes of devices
do not have _CID (e.g. SATA, USB). Instead, we can leverage ACPI _CLS,
which specifies PCI-defined class code (i.e. base-class, subclass and
programming interface). This patch adds support for matching ACPI devices using
the _CLS method.

To support loadable module, current design uses _HID or _CID to match device's
modalias. With the new way of matching with _CLS this would requires modification
to the current ACPI modalias key to include _CLS. This patch appends PCI-defined
class-code to the existing ACPI modalias as following.

    acpi:&lt;HID&gt;:&lt;CID1&gt;:&lt;CID2&gt;:..:&lt;CIDn&gt;:&lt;bbsspp&gt;:
E.g:
    # cat /sys/devices/platform/AMDI0600:00/modalias
    acpi:AMDI0600:010601:

where bb is th base-class code, ss is te sub-class code, and pp is the
programming interface code

Since there would not be _HID/_CID in the ACPI matching table of the driver,
this patch adds a field to acpi_device_id to specify the matching _CLS.

    static const struct acpi_device_id ahci_acpi_match[] = {
        { ACPI_DEVICE_CLASS(PCI_CLASS_STORAGE_SATA_AHCI, 0xffffff) },
        {},
    };

In this case, the corresponded entry in modules.alias file would be:

    alias acpi*:010601:* ahci_platform

Acked-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Reviewed-by: Hanjun Guo &lt;hanjun.guo@linaro.org&gt;
Signed-off-by: Suravee Suthikulpanit &lt;Suravee.Suthikulpanit@amd.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>
Device drivers typically use ACPI _HIDs/_CIDs listed in struct device_driver
acpi_match_table to match devices. However, for generic drivers, we do not
want to list _HID for all supported devices. Also, certain classes of devices
do not have _CID (e.g. SATA, USB). Instead, we can leverage ACPI _CLS,
which specifies PCI-defined class code (i.e. base-class, subclass and
programming interface). This patch adds support for matching ACPI devices using
the _CLS method.

To support loadable module, current design uses _HID or _CID to match device's
modalias. With the new way of matching with _CLS this would requires modification
to the current ACPI modalias key to include _CLS. This patch appends PCI-defined
class-code to the existing ACPI modalias as following.

    acpi:&lt;HID&gt;:&lt;CID1&gt;:&lt;CID2&gt;:..:&lt;CIDn&gt;:&lt;bbsspp&gt;:
E.g:
    # cat /sys/devices/platform/AMDI0600:00/modalias
    acpi:AMDI0600:010601:

where bb is th base-class code, ss is te sub-class code, and pp is the
programming interface code

Since there would not be _HID/_CID in the ACPI matching table of the driver,
this patch adds a field to acpi_device_id to specify the matching _CLS.

    static const struct acpi_device_id ahci_acpi_match[] = {
        { ACPI_DEVICE_CLASS(PCI_CLASS_STORAGE_SATA_AHCI, 0xffffff) },
        {},
    };

In this case, the corresponded entry in modules.alias file would be:

    alias acpi*:010601:* ahci_platform

Acked-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Reviewed-by: Hanjun Guo &lt;hanjun.guo@linaro.org&gt;
Signed-off-by: Suravee Suthikulpanit &lt;Suravee.Suthikulpanit@amd.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / LPSS: Fix up acpi_lpss_create_device()</title>
<updated>2015-07-06T22:31:47+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2015-07-06T22:31:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d3e13ff3c1aa2403d9a5f371baac088daeb8f56d'/>
<id>d3e13ff3c1aa2403d9a5f371baac088daeb8f56d</id>
<content type='text'>
Fix a return value (which should be a negative error code) and a
memory leak (the list allocated by acpi_dev_get_resources() needs
to be freed on ioremap() errors too) in acpi_lpss_create_device()
introduced by commit 4483d59e29fe 'ACPI / LPSS: check the result
of ioremap()'.

Fixes: 4483d59e29fe 'ACPI / LPSS: check the result of ioremap()'
Reported-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Cc: 4.0+ &lt;stable@vger.kernel.org&gt; # 4.0+
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>
Fix a return value (which should be a negative error code) and a
memory leak (the list allocated by acpi_dev_get_resources() needs
to be freed on ioremap() errors too) in acpi_lpss_create_device()
introduced by commit 4483d59e29fe 'ACPI / LPSS: check the result
of ioremap()'.

Fixes: 4483d59e29fe 'ACPI / LPSS: check the result of ioremap()'
Reported-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Cc: 4.0+ &lt;stable@vger.kernel.org&gt; # 4.0+
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / PNP: Reserve ACPI resources at the fs_initcall_sync stage</title>
<updated>2015-07-06T21:52:21+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.git/commit/?id=0294112ee3135fbd15eaa70015af8283642dd970'/>
<id>0294112ee3135fbd15eaa70015af8283642dd970</id>
<content type='text'>
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;
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>
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;
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>
</feed>
