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commit 83a62c51ba7b3c0bf45150c4eac7aefc6c785e94 upstream. On chromebooks we depend on wakeup count to identify the wakeup source. But currently USB devices do not increment the wakeup count when they trigger the remote wake. This patch addresses the same. Resume condition is reported differently on USB 2.0 and USB 3.0 devices. On USB 2.0 devices, a wake capable device, if wake enabled, drives resume signal to indicate a remote wake (USB 2.0 spec section 7.1.7.7). The upstream facing port then sets C_PORT_SUSPEND bit and reports a port change event (USB 2.0 spec section 11.24.2.7.2.3). Thus if a port has resumed before driving the resume signal from the host and C_PORT_SUSPEND is set, then the device attached to the given port might be the reason for the last system wakeup. Increment the wakeup count for the same. On USB 3.0 devices, a function may signal that it wants to exit from device suspend by sending a Function Wake Device Notification to the host (USB3.0 spec section 8.5.6.4) Thus on receiving the Function Wake, increment the wakeup count. Signed-off-by: Ravi Chandra Sadineni <ravisadineni@chromium.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.