3f9ee7da72
Back in the days when genpd supported intermediate power states of its devices, it made sense to check the PM_QOS_FLAG_NO_POWER_OFF in genpd_power_off(). This because the attached devices were all being put into low power state together when the PM domain was also being powered off. At this point, the flag PM_QOS_FLAG_NO_POWER_OFF is better checked by drivers from their ->runtime_suspend() callbacks, like in the usb_port_runtime_suspend(), for example. Or perhaps an even better option is to set the QoS resume latency constraint for the device to zero, which informs the runtime PM core to prevent the device from being runtime suspended. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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.