Commit Graph

7 Commits

Author SHA1 Message Date
Ulf Hansson 4ec4f05908 PM: runtime: Clarify documentation when callbacks are unassigned
Recent changes to the PM core allows ->runtime_suspend|resume callbacks to
be unassigned.

In the earlier behaviour the PM core would return -ENOSYS, when trying to
runtime resume a device, for example. Let's update the documentation to
clarify this.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-06-11 19:04:07 +02:00
Krzysztof Kozlowski c58e7ed28b PM: runtime: document common mistake with pm_runtime_get_sync()
pm_runtime_get_sync(), contradictory to intuition, does not drop the
runtime PM usage counter on errors which lead to several wrong usages in
drivers (missing the put).  pm_runtime_resume_and_get() was added as a
better implementation so document the preference of using it, hoping it
will stop bad patterns.

Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
[ rjw: Documentation change edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-05-31 14:17:13 +02:00
Alan Stern 2c412337cf PM: runtime: Add documentation for pm_runtime_resume_and_get()
Commit dd8088d5a8 ("PM: runtime: Add pm_runtime_resume_and_get to
deal with usage counter") added a new runtime-PM API function without
updating the documentation in runtime_pm.rst.

Add the missing documentation.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Fixes: dd8088d5a8 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-04-09 17:24:28 +02:00
Bjorn Helgaas 309663093c PM: runtime: Fix typos and grammar
Fix minor typos and grammatical issues.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-01-27 19:23:38 +01:00
Sakari Ailus c111566bea PM: runtime: Add pm_runtime_get_if_active()
pm_runtime_get_if_in_use() bumps up the PM-runtime usage count if it
is not equal to zero and the device's PM-runtime status is 'active'.
This works for drivers that do not use autoidle, but for those that
do, the function returns zero even when the device is active.

In order to maintain sane device state while the device is powered on
in the hope that it'll be needed, pm_runtime_get_if_active(dev, true)
returns a positive value if the device's PM-runtime status is 'active'
when it is called, in which case it also increments the device's usage
count.

If the second argument of pm_runtime_get_if_active() is 'false', the
function behaves just like pm_runtime_get_if_in_use(), so redefine
the latter as a wrapper around the former.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-03-04 11:01:18 +01:00
Bjorn Helgaas 1992b66d2f PM: Wrap documentation to fit in 80 columns
Wrap to 80 columns.  No textual change except to correct some "it's" that
should be "its".

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-20 12:16:37 +01:00
Mauro Carvalho Chehab 151f4e2bdc docs: power: convert docs to ReST and rename to *.rst
Convert the PM documents to ReST, in order to allow them to
build with Sphinx.

The conversion is actually:
  - add blank lines and indentation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
2019-06-14 16:08:36 -05:00