93c0970493
The link status value latches link-down events. To get the current status we read the register twice in genphy_update_link(). There's a potential risk that we miss a link-down event in polling mode. This may cause issues if the user e.g. connects his machine to a different network. On the other hand reading the latched value may cause issues in interrupt mode. Following scenario: - After boot link goes up - phy_start() is called triggering an aneg restart, hence link goes down and link-down info is latched. - After aneg has finished link goes up and triggers an interrupt. Interrupt handler reads link status, means it reads the latched "link is down" info. But there won't be another interrupt as long as link stays up, therefore phylib will never recognize that link is up. Deal with both scenarios by reading the register twice in interrupt mode only. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> 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.