6b6c150b84
When TX packet arrives, driver should leave deep PS state to make sure the DMA is working. After requested to leave deep PS state, driver needs to poll the PS state to check if the mode has been changed successfully. The driver used to check the state of the hardware every 20 msecs, which means upon the first failure of state check, the CPU is delayed 20 msecs for next check. This is harmful for some time-sensitive applications such as media players. So, use shorter delay time each check from 20 msecs to 100 usecs. The state should be changed in several tries. But we still need to reserve ~15 msecs in total in case of the state just took too long to be changed successfully. If the states of driver and the hardware is not synchronized, the power state could be locked forever, which mean we could never enter/leave the PS state. Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com> Reviewed-by: Chris Chiu <chiu@endlessm.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.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.