<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/pinctrl/spear, branch v4.2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Update Viresh Kumar's email address</title>
<updated>2015-07-17T23:39:53+00:00</updated>
<author>
<name>Viresh Kumar</name>
<email>viresh.kumar@linaro.org</email>
</author>
<published>2015-07-17T23:23:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=da89947b47a3a355f33a75d7672892c147ed880d'/>
<id>da89947b47a3a355f33a75d7672892c147ed880d</id>
<content type='text'>
Switch to my kernel.org alias instead of a badly named gmail address,
which I rarely use.

Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Switch to my kernel.org alias instead of a badly named gmail address,
which I rarely use.

Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pinctrl: make pinctrl_register() return proper error code</title>
<updated>2015-06-10T12:49:52+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2015-06-09T04:01:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=323de9efdf3e75d1dfb48003a52e59d6d9d4c7a5'/>
<id>323de9efdf3e75d1dfb48003a52e59d6d9d4c7a5</id>
<content type='text'>
Currently, pinctrl_register() just returns NULL on error, so the
callers can not know the exact reason of the failure.

Some of the pinctrl drivers return -EINVAL, some -ENODEV, and some
-ENOMEM on error of pinctrl_register(), although the error code
might be different from the real cause of the error.

This commit reworks pinctrl_register() to return the appropriate
error code and modifies all of the pinctrl drivers to use IS_ERR()
for the error checking and PTR_ERR() for getting the error code.

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Acked-by: Patrice Chotard &lt;patrice.chotard@st.com&gt;
Acked-by: Thierry Reding &lt;treding@nvidia.com&gt;
Acked-by: Heiko Stuebner &lt;heiko@sntech.de&gt;
Tested-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Acked-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Acked-by: Lee Jones &lt;lee@kernel.org&gt;
Acked-by: Sören Brinkmann &lt;soren.brinkmann@xilinx.com&gt;
Acked-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
Acked-by: Ray Jui &lt;rjui@broadcom.com&gt;
Acked-by: Antoine Tenart &lt;antoine.tenart@free-electrons.com&gt;
Acked-by: Hongzhou Yang &lt;hongzhou.yang@mediatek.com&gt;
Acked-by: Wei Chen &lt;Wei.Chen@csr.com&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, pinctrl_register() just returns NULL on error, so the
callers can not know the exact reason of the failure.

Some of the pinctrl drivers return -EINVAL, some -ENODEV, and some
-ENOMEM on error of pinctrl_register(), although the error code
might be different from the real cause of the error.

This commit reworks pinctrl_register() to return the appropriate
error code and modifies all of the pinctrl drivers to use IS_ERR()
for the error checking and PTR_ERR() for getting the error code.

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Acked-by: Patrice Chotard &lt;patrice.chotard@st.com&gt;
Acked-by: Thierry Reding &lt;treding@nvidia.com&gt;
Acked-by: Heiko Stuebner &lt;heiko@sntech.de&gt;
Tested-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Acked-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Acked-by: Lee Jones &lt;lee@kernel.org&gt;
Acked-by: Sören Brinkmann &lt;soren.brinkmann@xilinx.com&gt;
Acked-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
Acked-by: Ray Jui &lt;rjui@broadcom.com&gt;
Acked-by: Antoine Tenart &lt;antoine.tenart@free-electrons.com&gt;
Acked-by: Hongzhou Yang &lt;hongzhou.yang@mediatek.com&gt;
Acked-by: Wei Chen &lt;Wei.Chen@csr.com&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core</title>
<updated>2014-12-15T00:10:09+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-12-15T00:10:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e6b5be2be4e30037eb551e0ed09dd97bd00d85d3'/>
<id>e6b5be2be4e30037eb551e0ed09dd97bd00d85d3</id>
<content type='text'>
Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_&lt;level&gt;_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_&lt;level&gt;_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge Linus' tree to be be to apply submitted patches to newer code than</title>
<updated>2014-11-20T13:42:02+00:00</updated>
<author>
<name>Jiri Kosina</name>
<email>jkosina@suse.cz</email>
</author>
<published>2014-11-20T13:42:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a02001086bbfb4da35d1228bebc2f1b442db455f'/>
<id>a02001086bbfb4da35d1228bebc2f1b442db455f</id>
<content type='text'>
current trivial.git base
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
current trivial.git base
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Fix company name in module descriptions</title>
<updated>2014-10-29T13:36:36+00:00</updated>
<author>
<name>Masanari Iida</name>
<email>standby24x7@gmail.com</email>
</author>
<published>2014-10-16T15:09:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fe4e437229d43e3545416e63598a8476abeb0c01'/>
<id>fe4e437229d43e3545416e63598a8476abeb0c01</id>
<content type='text'>
This patch fix company name's spelling typo in module descriptions
and a Kconfig.

Signed-off-by: Masanari Iida &lt;standby24x7@gmail.com&gt;
Acked-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Acked-by: Chris Snook &lt;chris.snook@gmail.com&gt;
Acked-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch fix company name's spelling typo in module descriptions
and a Kconfig.

Signed-off-by: Masanari Iida &lt;standby24x7@gmail.com&gt;
Acked-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Acked-by: Chris Snook &lt;chris.snook@gmail.com&gt;
Acked-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pinctrl: spear: drop owner assignment from platform_drivers</title>
<updated>2014-10-20T14:21:25+00:00</updated>
<author>
<name>Wolfram Sang</name>
<email>wsa@the-dreams.de</email>
</author>
<published>2014-10-20T14:21:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5a9a1e8437c865b29f0807ce861a224a95d3121e'/>
<id>5a9a1e8437c865b29f0807ce861a224a95d3121e</id>
<content type='text'>
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang &lt;wsa@the-dreams.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pinctrl: clean up after enable refactoring</title>
<updated>2014-09-04T08:05:07+00:00</updated>
<author>
<name>Linus Walleij</name>
<email>linus.walleij@linaro.org</email>
</author>
<published>2014-09-03T11:02:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=03e9f0cac5da6af85758276cb4624caf5911f2b9'/>
<id>03e9f0cac5da6af85758276cb4624caf5911f2b9</id>
<content type='text'>
commit 2243a87d90b42eb38bc281957df3e57c712b5e56
"pinctrl: avoid duplicated calling enable_pinmux_setting for a pin"
removed the .disable callback from the struct pinmux_ops,
making the .enable() callback the only remaining callback.

However .enable() is a bad name as it seems to imply that a
muxing can also be disabled. Rename the callback to .set_mux()
and also take this opportunity to clean out any remaining
mentions of .disable() from the documentation.

Acked-by: Stephen Warren &lt;swarren@nvidia.com&gt;
Acked-by: Bjorn Andersson &lt;bjorn.andersson@sonymobile.com&gt;
Acked-by: Fan Wu &lt;fwu@marvell.com&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 2243a87d90b42eb38bc281957df3e57c712b5e56
"pinctrl: avoid duplicated calling enable_pinmux_setting for a pin"
removed the .disable callback from the struct pinmux_ops,
making the .enable() callback the only remaining callback.

However .enable() is a bad name as it seems to imply that a
muxing can also be disabled. Rename the callback to .set_mux()
and also take this opportunity to clean out any remaining
mentions of .disable() from the documentation.

Acked-by: Stephen Warren &lt;swarren@nvidia.com&gt;
Acked-by: Bjorn Andersson &lt;bjorn.andersson@sonymobile.com&gt;
Acked-by: Fan Wu &lt;fwu@marvell.com&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pinctrl: Make of_device_id array const</title>
<updated>2014-08-29T05:13:04+00:00</updated>
<author>
<name>Kiran Padwal</name>
<email>kiran.padwal21@gmail.com</email>
</author>
<published>2014-08-11T11:17:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5dfe10b43a91642845dcf281e02ca43ffde0d750'/>
<id>5dfe10b43a91642845dcf281e02ca43ffde0d750</id>
<content type='text'>
Make of_device_id array const, because all OF functions handle it as
const.

Signed-off-by: Kiran Padwal &lt;kiran.padwal21@gmail.com&gt;
Acked-by: Thierry Reding &lt;treding@nvidia.com&gt;
Acked-by: Stephen Warren &lt;swarren@nvidia.com&gt;
Acked-by: Shawn Guo &lt;shawn.guo@linaro.org&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make of_device_id array const, because all OF functions handle it as
const.

Signed-off-by: Kiran Padwal &lt;kiran.padwal21@gmail.com&gt;
Acked-by: Thierry Reding &lt;treding@nvidia.com&gt;
Acked-by: Stephen Warren &lt;swarren@nvidia.com&gt;
Acked-by: Shawn Guo &lt;shawn.guo@linaro.org&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pinctrl: remove all usage of gpio_remove ret val in driver/pinctl</title>
<updated>2014-07-22T14:34:12+00:00</updated>
<author>
<name>abdoulaye berthe</name>
<email>berthe.ab@gmail.com</email>
</author>
<published>2014-07-12T20:30:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b4e7c55dabf611cf5cccd1554fec06f72e1c9faf'/>
<id>b4e7c55dabf611cf5cccd1554fec06f72e1c9faf</id>
<content type='text'>
Signed-off-by: abdoulaye berthe &lt;berthe.ab@gmail.com&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: abdoulaye berthe &lt;berthe.ab@gmail.com&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pinctrl: avoid duplicated calling enable_pinmux_setting for a pin</title>
<updated>2014-07-11T12:08:26+00:00</updated>
<author>
<name>Fan Wu</name>
<email>fwu@marvell.com</email>
</author>
<published>2014-06-09T01:37:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2243a87d90b42eb38bc281957df3e57c712b5e56'/>
<id>2243a87d90b42eb38bc281957df3e57c712b5e56</id>
<content type='text'>
What the patch does:
1. Call pinmux_disable_setting ahead of pinmux_enable_setting
  each time pinctrl_select_state is called
2. Remove the HW disable operation in pinmux_disable_setting function.
3. Remove the disable ops in struct pinmux_ops
4. Remove all the disable ops users in current code base.

Notes:
1. Great thanks for the suggestion from Linus, Tony Lindgren and
   Stephen Warren and Everyone that shared comments on this patch.
2. The patch also includes comment fixes from Stephen Warren.

The reason why we do this:
1. To avoid duplicated calling of the enable_setting operation
   without disabling operation inbetween which will let the pin
   descriptor desc-&gt;mux_usecount increase monotonously.
2. The HW pin disable operation is not useful for any of the
   existing platforms.
   And this can be used to avoid the HW glitch after using the
   item #1 modification.

In the following case, the issue can be reproduced:
1. There is a driver that need to switch pin state dynamically,
   e.g. between "sleep" and "default" state
2. The pin setting configuration in a DTS node may be like this:

  component a {
	pinctrl-names = "default", "sleep";
	pinctrl-0 = &lt;&amp;a_grp_setting &amp;c_grp_setting&gt;;
	pinctrl-1 = &lt;&amp;b_grp_setting &amp;c_grp_setting&gt;;
  }

  The "c_grp_setting" config node is totally identical, maybe like
  following one:

  c_grp_setting: c_grp_setting {
	pinctrl-single,pins = &lt;GPIO48 AF6&gt;;
  }

3. When switching the pin state in the following official pinctrl
   sequence:
	pin = pinctrl_get();
	state = pinctrl_lookup_state(wanted_state);
	pinctrl_select_state(state);
	pinctrl_put();

Test Result:
1. The switch is completed as expected, that is: the device's
   pin configuration is changed according to the description in the
   "wanted_state" group setting
2. The "desc-&gt;mux_usecount" of the corresponding pins in "c_group"
   is increased without being decreased, because the "desc" is for
   each physical pin while the setting is for each setting node
   in the DTS.
   Thus, if the "c_grp_setting" in pinctrl-0 is not disabled ahead
   of enabling "c_grp_setting" in pinctrl-1, the desc-&gt;mux_usecount
   will keep increasing without any chance to be decreased.

According to the comments in the original code, only the setting,
in old state but not in new state, will be "disabled" (calling
pinmux_disable_setting), which is correct logic but not intact. We
still need consider case that the setting is in both old state
and new state. We can do this in the following two ways:

1. Avoid to "enable"(calling pinmux_enable_setting) the "same pin
   setting" repeatedly
2. "Disable"(calling pinmux_disable_setting) the "same pin setting",
   actually two setting instances, ahead of enabling them.

Analysis:
1. The solution #2 is better because it can avoid too much
   iteration.
2. If we disable all of the settings in the old state and one of
   the setting(s) exist in the new state, the pins mux function
   change may happen when some SoC vendors defined the
   "pinctrl-single,function-off"
   in their DTS file.
   old_setting =&gt; disabled_setting =&gt; new_setting.
3. In the pinmux framework, when a pin state is switched, the
   setting in the old state should be marked as "disabled".

Conclusion:
1. To Remove the HW disabling operation to above the glitch mentioned
   above.
2. Handle the issue mentioned above by disabling all of the settings
   in old state and then enable the all of the settings in new state.

Signed-off-by: Fan Wu &lt;fwu@marvell.com&gt;
Acked-by: Stephen Warren &lt;swarren@nvidia.com&gt;
Acked-by: Patrice Chotard &lt;patrice.chotard@st.com&gt;
Acked-by: Heiko Stuebner &lt;heiko@sntech.de&gt;
Acked-by: Maxime Coquelin &lt;maxime.coquelin@st.com&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
What the patch does:
1. Call pinmux_disable_setting ahead of pinmux_enable_setting
  each time pinctrl_select_state is called
2. Remove the HW disable operation in pinmux_disable_setting function.
3. Remove the disable ops in struct pinmux_ops
4. Remove all the disable ops users in current code base.

Notes:
1. Great thanks for the suggestion from Linus, Tony Lindgren and
   Stephen Warren and Everyone that shared comments on this patch.
2. The patch also includes comment fixes from Stephen Warren.

The reason why we do this:
1. To avoid duplicated calling of the enable_setting operation
   without disabling operation inbetween which will let the pin
   descriptor desc-&gt;mux_usecount increase monotonously.
2. The HW pin disable operation is not useful for any of the
   existing platforms.
   And this can be used to avoid the HW glitch after using the
   item #1 modification.

In the following case, the issue can be reproduced:
1. There is a driver that need to switch pin state dynamically,
   e.g. between "sleep" and "default" state
2. The pin setting configuration in a DTS node may be like this:

  component a {
	pinctrl-names = "default", "sleep";
	pinctrl-0 = &lt;&amp;a_grp_setting &amp;c_grp_setting&gt;;
	pinctrl-1 = &lt;&amp;b_grp_setting &amp;c_grp_setting&gt;;
  }

  The "c_grp_setting" config node is totally identical, maybe like
  following one:

  c_grp_setting: c_grp_setting {
	pinctrl-single,pins = &lt;GPIO48 AF6&gt;;
  }

3. When switching the pin state in the following official pinctrl
   sequence:
	pin = pinctrl_get();
	state = pinctrl_lookup_state(wanted_state);
	pinctrl_select_state(state);
	pinctrl_put();

Test Result:
1. The switch is completed as expected, that is: the device's
   pin configuration is changed according to the description in the
   "wanted_state" group setting
2. The "desc-&gt;mux_usecount" of the corresponding pins in "c_group"
   is increased without being decreased, because the "desc" is for
   each physical pin while the setting is for each setting node
   in the DTS.
   Thus, if the "c_grp_setting" in pinctrl-0 is not disabled ahead
   of enabling "c_grp_setting" in pinctrl-1, the desc-&gt;mux_usecount
   will keep increasing without any chance to be decreased.

According to the comments in the original code, only the setting,
in old state but not in new state, will be "disabled" (calling
pinmux_disable_setting), which is correct logic but not intact. We
still need consider case that the setting is in both old state
and new state. We can do this in the following two ways:

1. Avoid to "enable"(calling pinmux_enable_setting) the "same pin
   setting" repeatedly
2. "Disable"(calling pinmux_disable_setting) the "same pin setting",
   actually two setting instances, ahead of enabling them.

Analysis:
1. The solution #2 is better because it can avoid too much
   iteration.
2. If we disable all of the settings in the old state and one of
   the setting(s) exist in the new state, the pins mux function
   change may happen when some SoC vendors defined the
   "pinctrl-single,function-off"
   in their DTS file.
   old_setting =&gt; disabled_setting =&gt; new_setting.
3. In the pinmux framework, when a pin state is switched, the
   setting in the old state should be marked as "disabled".

Conclusion:
1. To Remove the HW disabling operation to above the glitch mentioned
   above.
2. Handle the issue mentioned above by disabling all of the settings
   in old state and then enable the all of the settings in new state.

Signed-off-by: Fan Wu &lt;fwu@marvell.com&gt;
Acked-by: Stephen Warren &lt;swarren@nvidia.com&gt;
Acked-by: Patrice Chotard &lt;patrice.chotard@st.com&gt;
Acked-by: Heiko Stuebner &lt;heiko@sntech.de&gt;
Acked-by: Maxime Coquelin &lt;maxime.coquelin@st.com&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
</pre>
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</content>
</entry>
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