f1c0db40a3
Add the ability to handle USB wake events from USB devices when in S2 mode. Typically there is some additional configuration needed to tell the USB device to generate the wake event when suspended but this varies with the different USB device classes. For example, on USB Ethernet dongles, ethtool should be used to enable the magic packet wake functionality in the dongle. NOTE: This requires that the "power/wakeup" sysfs entry for the USB device generating the wakeup be set to "enabled". This functionality requires a special hardware sideband path that will trigger the AON_PM_L2 interrupt needed to wake the system from S2 even though the USB host controllers are in IDDQ (low power state) and most USB related clocks are shut off. For the sideband signaling to work we need to leave the usbx_freerun clock running, but this clock consumes very little power by design. There's a bug in the XHCI wake hardware so only EHCI/OHCI wake is currently supported. Signed-off-by: Al Cooper <alcooperx@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.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.