503d6e5fb8
[ Upstream commit e3e56c050ab6e3f1bd811f0787f50709017543e4 ]
The general expectation is that powering on a power-domain should make
the power domain deliver some power, and if a specific performance state
is needed further requests has to be made.
But in contrast with other power-domain implementations (e.g. rpmpd) the
RPMh does not have an interface to enable the power, so the driver has
to vote for a particular corner (performance level) in rpmh_power_on().
But the corner is never initialized, so a typical request to simply
enable the power domain would not actually turn on the hardware. Further
more, when no more clients vote for a performance state (i.e. the
aggregated vote is 0) the power domain would be turned off.
Fix both of these issues by always voting for a corner with non-zero
value, when the power domain is enabled.
The tracking of the lowest non-zero corner is performed to handle the
corner case if there's ever a domain with a non-zero lowest corner, in
which case both rpmh_power_on() and rpmh_rpmhpd_set_performance_state()
would be allowed to use this lowest corner.
Fixes: 279b7e8a62 ("soc: qcom: rpmhpd: Add RPMh power domain driver")
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20211005033732.2284447-1-bjorn.andersson@linaro.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.