Some Micrel KSZ8041NL PHY chips exhibit continuous RX errors after using the power down mode bit (0.11). If the PHY is taken out of power down mode in a certain temperature range, the PHY enters a weird state which leads to continuously reporting RX errors. In that state, the MAC is not able to receive or send any Ethernet frames and the activity LED is constantly blinking. Since Linux is using the suspend callback when the interface is taken down, ending up in that state can easily happen during a normal startup. Micrel confirmed the issue in errata DS80000700A [*], caused by abnormal clock recovery when using power down mode. Even the latest revision (A4, Revision ID 0x1513) seems to suffer that problem, and according to the errata is not going to be fixed. Remove the suspend/resume callback to avoid using the power down mode completely. [*] https://ww1.microchip.com/downloads/en/DeviceDoc/80000700A.pdf Fixes: 1a5465f5d6a2 ("phy/micrel: Add suspend/resume support to Micrel PHYs") Signed-off-by: Stefan Agner <stefan@agner.ch> Acked-by: Marcel Ziswiler <marcel.ziswiler@toradex.com> Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.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.
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