<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/opp, branch v6.5.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>OPP: Properly propagate error along when failing to get icc_path</title>
<updated>2023-06-27T02:05:14+00:00</updated>
<author>
<name>Andrew Halaney</name>
<email>ahalaney@redhat.com</email>
</author>
<published>2023-06-26T13:46:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5fb2864cbd50a84a73af4fdd900b31f2daddea34'/>
<id>5fb2864cbd50a84a73af4fdd900b31f2daddea34</id>
<content type='text'>
fa155f4f8348 ("OPP: Use dev_err_probe() when failing to get icc_path")
failed to actually use the error it was trying to log:

    smatch warnings:
    drivers/opp/of.c:516 dev_pm_opp_of_find_icc_paths() warn: passing zero to 'dev_err_probe'

Make sure to use the right error and pass it along.

Fixes: fa155f4f8348 ("OPP: Use dev_err_probe() when failing to get icc_path")
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Reported-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Closes: https://lore.kernel.org/r/202306262008.guNLgjt6-lkp@intel.com/
Signed-off-by: Andrew Halaney &lt;ahalaney@redhat.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
fa155f4f8348 ("OPP: Use dev_err_probe() when failing to get icc_path")
failed to actually use the error it was trying to log:

    smatch warnings:
    drivers/opp/of.c:516 dev_pm_opp_of_find_icc_paths() warn: passing zero to 'dev_err_probe'

Make sure to use the right error and pass it along.

Fixes: fa155f4f8348 ("OPP: Use dev_err_probe() when failing to get icc_path")
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Reported-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Closes: https://lore.kernel.org/r/202306262008.guNLgjt6-lkp@intel.com/
Signed-off-by: Andrew Halaney &lt;ahalaney@redhat.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>OPP: Use dev_err_probe() when failing to get icc_path</title>
<updated>2023-06-26T06:40:26+00:00</updated>
<author>
<name>Andrew Halaney</name>
<email>ahalaney@redhat.com</email>
</author>
<published>2023-06-23T15:53:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fa155f4f834882a79788218aea4914568b41dd0f'/>
<id>fa155f4f834882a79788218aea4914568b41dd0f</id>
<content type='text'>
This, in tandem with dynamic debug, can print useful information about
-EPROBE_DEFFER like below, and keeps similar behavior for other errors:

    [   16.561072] cpu cpu0: error -EPROBE_DEFER: dev_pm_opp_of_find_icc_paths: Unable to get path0
    [   16.575777] platform 18591000.cpufreq: deferred probe pending

Signed-off-by: Andrew Halaney &lt;ahalaney@redhat.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This, in tandem with dynamic debug, can print useful information about
-EPROBE_DEFFER like below, and keeps similar behavior for other errors:

    [   16.561072] cpu cpu0: error -EPROBE_DEFER: dev_pm_opp_of_find_icc_paths: Unable to get path0
    [   16.575777] platform 18591000.cpufreq: deferred probe pending

Signed-off-by: Andrew Halaney &lt;ahalaney@redhat.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>OPP: Simplify the over-designed pstate &lt;-&gt; level dance</title>
<updated>2023-06-19T04:20:09+00:00</updated>
<author>
<name>Viresh Kumar</name>
<email>viresh.kumar@linaro.org</email>
</author>
<published>2023-06-14T09:59:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7c41cdcd3bbee5d49de9d4821b15e49d155ff22b'/>
<id>7c41cdcd3bbee5d49de9d4821b15e49d155ff22b</id>
<content type='text'>
While adding support for "performance states" in the OPP and genpd core,
it was decided to set the `pstate` field via genpd's
pm_genpd_opp_to_performance_state() helper, to allow platforms to set
`pstate` even if they don't have a corresponding `level` field in the DT
OPP tables (More details are present in commit 6e41766a6a50 ("PM /
Domain: Implement of_genpd_opp_to_performance_state()")).

Revisiting that five years later clearly suggests that it was
over-designed as all current users are eventually using the `level`
value only.

The previous commit already added necessary checks to make sure pstate
is only used for genpd tables. Lets now simplify this a little, and use
`level` directly and remove `pstate` field altogether.

Suggested-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
While adding support for "performance states" in the OPP and genpd core,
it was decided to set the `pstate` field via genpd's
pm_genpd_opp_to_performance_state() helper, to allow platforms to set
`pstate` even if they don't have a corresponding `level` field in the DT
OPP tables (More details are present in commit 6e41766a6a50 ("PM /
Domain: Implement of_genpd_opp_to_performance_state()")).

Revisiting that five years later clearly suggests that it was
over-designed as all current users are eventually using the `level`
value only.

The previous commit already added necessary checks to make sure pstate
is only used for genpd tables. Lets now simplify this a little, and use
`level` directly and remove `pstate` field altogether.

Suggested-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>OPP: pstate is only valid for genpd OPP tables</title>
<updated>2023-06-19T04:20:02+00:00</updated>
<author>
<name>Viresh Kumar</name>
<email>viresh.kumar@linaro.org</email>
</author>
<published>2023-06-14T10:27:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=84cb7ff35fcf7c0b552f553a3f2db9c3e92fc707'/>
<id>84cb7ff35fcf7c0b552f553a3f2db9c3e92fc707</id>
<content type='text'>
It is not very clear right now that the `pstate` field is only valid for
genpd OPP tables and not consumer tables. And there is no checking for
the same at various places.

Add checks in place to verify that and make it clear to the reader.

Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Reviewed-by: Bjorn Andersson &lt;quic_bjorande@quicinc.com&gt;
Tested-by: Bjorn Andersson &lt;quic_bjorande@quicinc.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It is not very clear right now that the `pstate` field is only valid for
genpd OPP tables and not consumer tables. And there is no checking for
the same at various places.

Add checks in place to verify that and make it clear to the reader.

Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Reviewed-by: Bjorn Andersson &lt;quic_bjorande@quicinc.com&gt;
Tested-by: Bjorn Andersson &lt;quic_bjorande@quicinc.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>OPP: don't drop performance constraint on OPP table removal</title>
<updated>2023-06-14T09:24:01+00:00</updated>
<author>
<name>Viresh Kumar</name>
<email>viresh.kumar@linaro.org</email>
</author>
<published>2023-06-14T07:20:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=04bd2eafee153b9cc4b411d4a24d32b1ec2ce41c'/>
<id>04bd2eafee153b9cc4b411d4a24d32b1ec2ce41c</id>
<content type='text'>
This code was added (long back) by commit 009acd196fc8 ("PM / OPP:
Support updating performance state of device's power domain") and at
that time the `opp-&gt;pstate` field was used to store the performance
state required by a device's OPP.

Over time that changed and the `-&gt;pstate` field is now used only for
genpd devices and consumer devices access that via the required-opps
instead.

Because of all these changes, _opp_table_kref_release() now drops the
constraint only when the genpd's OPP table gets freed and not the
device's. Which is definitely not what we wanted. And dropping the
constraint doesn't have much meaning as the genpd itself is going away.

Moreover, if we want to drop constraints here, then just dropping the
performance constraint alone isn't sufficient as there are other
resource constraints like clk, regulator, etc. too, which must be
handled.

Probably the right thing to do here is to leave this decision to the
consumers, which can call `dev_pm_opp_set_rate(dev, 0)` or similar APIs
to drop all constraints properly. Which many of the consumers already
do.

Remove the special code, which is broken anyway.

Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This code was added (long back) by commit 009acd196fc8 ("PM / OPP:
Support updating performance state of device's power domain") and at
that time the `opp-&gt;pstate` field was used to store the performance
state required by a device's OPP.

Over time that changed and the `-&gt;pstate` field is now used only for
genpd devices and consumer devices access that via the required-opps
instead.

Because of all these changes, _opp_table_kref_release() now drops the
constraint only when the genpd's OPP table gets freed and not the
device's. Which is definitely not what we wanted. And dropping the
constraint doesn't have much meaning as the genpd itself is going away.

Moreover, if we want to drop constraints here, then just dropping the
performance constraint alone isn't sufficient as there are other
resource constraints like clk, regulator, etc. too, which must be
handled.

Probably the right thing to do here is to leave this decision to the
consumers, which can call `dev_pm_opp_set_rate(dev, 0)` or similar APIs
to drop all constraints properly. Which many of the consumers already
do.

Remove the special code, which is broken anyway.

Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>OPP: Protect `lazy_opp_tables` list with `opp_table_lock`</title>
<updated>2023-06-14T03:50:50+00:00</updated>
<author>
<name>Viresh Kumar</name>
<email>viresh.kumar@linaro.org</email>
</author>
<published>2023-06-08T07:40:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=64aaeb708245acdcbe51cf30c84418668c044d80'/>
<id>64aaeb708245acdcbe51cf30c84418668c044d80</id>
<content type='text'>
The `opp_table_lock` lock is already used to protect the list elsewhere,
use it while adding or removing entries from it.

Reported-by: Stephan Gerhold &lt;stephan.gerhold@kernkonzept.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Tested-by: Stephan Gerhold &lt;stephan.gerhold@kernkonzept.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The `opp_table_lock` lock is already used to protect the list elsewhere,
use it while adding or removing entries from it.

Reported-by: Stephan Gerhold &lt;stephan.gerhold@kernkonzept.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Tested-by: Stephan Gerhold &lt;stephan.gerhold@kernkonzept.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>OPP: Staticize `lazy_opp_tables` in of.c</title>
<updated>2023-06-08T07:25:07+00:00</updated>
<author>
<name>Viresh Kumar</name>
<email>viresh.kumar@linaro.org</email>
</author>
<published>2023-06-08T07:25:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=167eb2bd947d9c04b0f6f1a5495ce4a99eeab598'/>
<id>167eb2bd947d9c04b0f6f1a5495ce4a99eeab598</id>
<content type='text'>
`lazy_opp_tables` is only used in of.c, move it there and mark it
`static`.

Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
`lazy_opp_tables` is only used in of.c, move it there and mark it
`static`.

Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>opp: Fix use-after-free in lazy_opp_tables after probe deferral</title>
<updated>2023-05-31T03:51:41+00:00</updated>
<author>
<name>Stephan Gerhold</name>
<email>stephan.gerhold@kernkonzept.com</email>
</author>
<published>2023-05-30T15:54:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b2a2ab039bd58f51355e33d7d3fc64605d7f870d'/>
<id>b2a2ab039bd58f51355e33d7d3fc64605d7f870d</id>
<content type='text'>
When dev_pm_opp_of_find_icc_paths() in _allocate_opp_table() returns
-EPROBE_DEFER, the opp_table is freed again, to wait until all the
interconnect paths are available.

However, if the OPP table is using required-opps then it may already
have been added to the global lazy_opp_tables list. The error path
does not remove the opp_table from the list again.

This can cause crashes later when the provider of the required-opps
is added, since we will iterate over OPP tables that have already been
freed. E.g.:

  Unable to handle kernel NULL pointer dereference when read
  CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.4.0-rc3
  PC is at _of_add_opp_table_v2 (include/linux/of.h:949
  drivers/opp/of.c:98 drivers/opp/of.c:344 drivers/opp/of.c:404
  drivers/opp/of.c:1032) -&gt; lazy_link_required_opp_table()

Fix this by calling _of_clear_opp_table() to remove the opp_table from
the list and clear other allocated resources. While at it, also add the
missing mutex_destroy() calls in the error path.

Cc: stable@vger.kernel.org
Suggested-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Fixes: 7eba0c7641b0 ("opp: Allow lazy-linking of required-opps")
Signed-off-by: Stephan Gerhold &lt;stephan.gerhold@kernkonzept.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When dev_pm_opp_of_find_icc_paths() in _allocate_opp_table() returns
-EPROBE_DEFER, the opp_table is freed again, to wait until all the
interconnect paths are available.

However, if the OPP table is using required-opps then it may already
have been added to the global lazy_opp_tables list. The error path
does not remove the opp_table from the list again.

This can cause crashes later when the provider of the required-opps
is added, since we will iterate over OPP tables that have already been
freed. E.g.:

  Unable to handle kernel NULL pointer dereference when read
  CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.4.0-rc3
  PC is at _of_add_opp_table_v2 (include/linux/of.h:949
  drivers/opp/of.c:98 drivers/opp/of.c:344 drivers/opp/of.c:404
  drivers/opp/of.c:1032) -&gt; lazy_link_required_opp_table()

Fix this by calling _of_clear_opp_table() to remove the opp_table from
the list and clear other allocated resources. While at it, also add the
missing mutex_destroy() calls in the error path.

Cc: stable@vger.kernel.org
Suggested-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Fixes: 7eba0c7641b0 ("opp: Allow lazy-linking of required-opps")
Signed-off-by: Stephan Gerhold &lt;stephan.gerhold@kernkonzept.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>OPP: rate-limit debug messages when no change in OPP is required</title>
<updated>2023-05-22T03:41:40+00:00</updated>
<author>
<name>Adrián Larumbe</name>
<email>adrian.larumbe@collabora.com</email>
</author>
<published>2023-05-20T17:00:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9e28f7a74581204807f20ae46568939038e327aa'/>
<id>9e28f7a74581204807f20ae46568939038e327aa</id>
<content type='text'>
Otherwise, when enabling a debug build and dynamic debug in the kernel, it
quickly floods the kernel ring buffer and makes debugging of other
subsystems almost impossible, unless manually disabled.

Signed-off-by: Adrián Larumbe &lt;adrian.larumbe@collabora.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Otherwise, when enabling a debug build and dynamic debug in the kernel, it
quickly floods the kernel ring buffer and makes debugging of other
subsystems almost impossible, unless manually disabled.

Signed-off-by: Adrián Larumbe &lt;adrian.larumbe@collabora.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'devicetree-for-6.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux</title>
<updated>2023-04-27T17:09:05+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-04-27T17:09:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cb6fe2ceb667eb78f252d473b03deb23999ab1cf'/>
<id>cb6fe2ceb667eb78f252d473b03deb23999ab1cf</id>
<content type='text'>
Pull more devicetree updates from Rob Herring:

 - First part of DT header detangling dropping cpu.h from of_device.h
   and replacing some includes with forward declarations. A handful of
   drivers needed some adjustment to their includes as a result.

 - Refactor of_device.h to be used by bus drivers rather than various
   device drivers. This moves non-bus related functions out of
   of_device.h. The end goal is for of_platform.h and of_device.h to
   stop including each other.

 - Refactor open coded parsing of "ranges" in some bus drivers to use DT
   address parsing functions

 - Add some new address parsing functions of_property_read_reg(),
   of_range_count(), and of_range_to_resource() in preparation to
   convert more open coded parsing of DT addresses to use them.

 - Treewide clean-ups to use of_property_read_bool() and
   of_property_present() as appropriate. The ones here are the ones that
   didn't get picked up elsewhere.

* tag 'devicetree-for-6.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (34 commits)
  bus: tegra-gmi: Replace of_platform.h with explicit includes
  hte: Use of_property_present() for testing DT property presence
  w1: w1-gpio: Use of_property_read_bool() for boolean properties
  virt: fsl: Use of_property_present() for testing DT property presence
  soc: fsl: Use of_property_present() for testing DT property presence
  sbus: display7seg: Use of_property_read_bool() for boolean properties
  sparc: Use of_property_read_bool() for boolean properties
  sparc: Use of_property_present() for testing DT property presence
  bus: mvebu-mbus: Remove open coded "ranges" parsing
  of/address: Add of_property_read_reg() helper
  of/address: Add of_range_count() helper
  of/address: Add support for 3 address cell bus
  of/address: Add of_range_to_resource() helper
  of: unittest: Add bus address range parsing tests
  of: Drop cpu.h include from of_device.h
  OPP: Adjust includes to remove of_device.h
  irqchip: loongson-eiointc: Add explicit include for cpuhotplug.h
  cpuidle: Adjust includes to remove of_device.h
  cpufreq: sun50i: Add explicit include for cpu.h
  cpufreq: Adjust includes to remove of_device.h
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more devicetree updates from Rob Herring:

 - First part of DT header detangling dropping cpu.h from of_device.h
   and replacing some includes with forward declarations. A handful of
   drivers needed some adjustment to their includes as a result.

 - Refactor of_device.h to be used by bus drivers rather than various
   device drivers. This moves non-bus related functions out of
   of_device.h. The end goal is for of_platform.h and of_device.h to
   stop including each other.

 - Refactor open coded parsing of "ranges" in some bus drivers to use DT
   address parsing functions

 - Add some new address parsing functions of_property_read_reg(),
   of_range_count(), and of_range_to_resource() in preparation to
   convert more open coded parsing of DT addresses to use them.

 - Treewide clean-ups to use of_property_read_bool() and
   of_property_present() as appropriate. The ones here are the ones that
   didn't get picked up elsewhere.

* tag 'devicetree-for-6.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (34 commits)
  bus: tegra-gmi: Replace of_platform.h with explicit includes
  hte: Use of_property_present() for testing DT property presence
  w1: w1-gpio: Use of_property_read_bool() for boolean properties
  virt: fsl: Use of_property_present() for testing DT property presence
  soc: fsl: Use of_property_present() for testing DT property presence
  sbus: display7seg: Use of_property_read_bool() for boolean properties
  sparc: Use of_property_read_bool() for boolean properties
  sparc: Use of_property_present() for testing DT property presence
  bus: mvebu-mbus: Remove open coded "ranges" parsing
  of/address: Add of_property_read_reg() helper
  of/address: Add of_range_count() helper
  of/address: Add support for 3 address cell bus
  of/address: Add of_range_to_resource() helper
  of: unittest: Add bus address range parsing tests
  of: Drop cpu.h include from of_device.h
  OPP: Adjust includes to remove of_device.h
  irqchip: loongson-eiointc: Add explicit include for cpuhotplug.h
  cpuidle: Adjust includes to remove of_device.h
  cpufreq: sun50i: Add explicit include for cpu.h
  cpufreq: Adjust includes to remove of_device.h
  ...
</pre>
</div>
</content>
</entry>
</feed>
