58581478a7
Some SFP modules uses RX_LOS for link indication. In such cases link will be always up, even without cable connected. RX_LOS changes will trigger link_up()/link_down() upstream operations. Thus, check that SFP link is operational before actual read link status. If there is no SFP cage connected to the tranciever, check only PMD Recieve Signal Detect register. Signed-off-by: Ivan Bornyakov <i.bornyakov@metrotek.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
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.